Classes of Polymeric Materials
Professor Joe Greene
CSU, CHICO
1
Topics
• Introduction
• Thermoplastics
– General
– Commercial plastics
• Thermosets
– General
– Commercial thermosets
• Elastomers
– General
– Commercial elastomers
2
Introduction
• Polymeric materials can be either
– Thermoplastics, thermosets, and elastomers.
– Each section is presented in appropriate groups
• Thermoplastics come in a variety of forms
– Pellets, powder (1-100 microns), flake, chip, cube, dice,
– Shipped in packages of choice
– Bags (50 lbs), drums (200 lbs), boxes, cartons, gaylords (1000 lb),
– Tank-truck loads (15 tons), rail cars (40 – 80 tons)
• Bulk supplies are stored in silos and conveyed pneumatically
• Thermosets are supplied in powder or liquid form
– Supplied in drums, tank-trucks, and railroad cars.
• Rubbers are supplied in bale form.
3
Commercial Thermoplastics
• Olefins
– Unsaturated, aliphatic hydrocarbons made from ethylene gas
– Ethylene is produced by cracking higher hydrocarbons of natural gas or
petroleum
• LDPE commercialized in 1939 in high pressure process
• Branched, high pressure, and low density polyethylene
• HDPE commercialized in 1957 in low pressure process
• Linear, low pressure, high density
• The higher the density the higher the crystallinity
• Higher the crystallinity the higher the modulus, strength, chemical
resistance,
• PE grades are classified according to melt index (viscosity) which is a
strong indicator of molecular weight.
– Injection molding requires high flow, extrusion grade is highly elastic,
thermoforming grade requires high viscosity or consistency
4
Principal Olefin Monomers
• Ethylene
Propylene
H H
H
H
C C
C
C
H H
CH3
H
• Butene-1
4-Methylpentene
H
H
H
H
C
C
C
C
C2H5 H
C5H6 H
5
CH3
Several Olefin Polymers
• Polyethylene
Polypropylene
H H
H
H
C C
C
C
CH3
H
H H
n
• Polyisobutene
Polymethylpentene
H
H
H
H
C
C
C
C
C2H5 H
n
n
C5H6 H
CH3
n
6
Polymers Derived from Ethylene Monomer
X Position
Material Name
Abbreviation
H
Cl
Methyl group
Benzene ring
CN
OOCCH3
OH
COOCH3
F
Polyethylene
Polyvinyl chloride
Polypropylene
Polystyrene
Polyacrylonitrile
Polyvinyl acetate
Polyvinyl alcohol
Polymethyl acrylate
Polyvinyl fluoride
PE
PVC
PP
PS
PAN
PvaC
PVA
PMA
PVF
Note:
Methyl Group is:
|
H–C–H
|
H
Benzene ring is:
X Position
Y Position
Material Name
Abbreviation
F
Cl
CH3 (Methyl group)
COOCH3
F
Cl
CH3
CH3
Polyvinylidene fluoride
Polyvinyl dichloride
Polyisobutylene
Polymethyl methacrylate
PVDF
PVDC
PB
PMMA
7
Addition Polymerization of PE
• Polyethylene produced with low (Ziegler) or high pressure (ICI)
• Polyethylene produced with linear or branched chains
…
…
H H
H H
H H
H H
H H
C C
C C
C C
C C
C C
H H
H H
H H
OR
H H
H H
H H
H H
H H
H H
H H
C C
C C
C C
C C
C C
H H
H H
H
H H
H H
…
…
8
Mechanical Properties of Polyethylene
• Type 1: (Branched) Low Density of 0.910 - 0.925 g/cc
• Type 2: Medium Density of 0.926 - 0.940 g/cc
• Type 3: High Density of 0.941 - 0.959 g/cc
• Type 4: (Linear) High Density to ultra high density > 0.959
Mechanical Properties
Branched Low
Density
Density
0.91- 0.925
Medium
Density
0.926- 0.94
High
Density
0.941-0.95
Linear High Density
0.959-0.965
Crystallinity
30% to 50%
50% to 70%
70% to 80%
80% to 91%
Molecular
Weight
Tensile
Strength, psi
Tensile
Modulus, psi
Tensile
Elongation, %
Impact Strength
10K to 30K
30K to 50K
50K to 250K
250K to 1.5M
600 - 2,300
1,200 - 3,000
3,100 - 5,500
5,000 – 6,000
25K – 41K
38K – 75 K
100% - 650%
100%- 965%
150K – 158
150K – 158 K
K
10% - 1300% 10% - 1300%
No break
1.0 – no
break
D50 – D60
ft-lb/in
Hardness, Shore D44 – D50
0.4 – 4.0
0.4 – 4.0
D60 – D70
D66 – D73
9
Physical Properties of Polyethylene
Physical Properties of polyethylene
Branched Low Medium Density
Density
Optical
Transparent to Transparent to
opaque
opaque
Tmelt
98 – 115 C
122 – 124 C
High
Density
Transparent to
opaque
130 – 137 C
Linear High Density
Transparent to opaque
130 –137 C
Tg
-100 C
H20 Absorption Low < 0.01
-100 C
Low < 0.01
-100 C
Low < 0.01
-100 C
Low < 0.01
Oxidation
Resistance
UV Resistance
Low, oxides
readily
Low, Crazes
readily
Resistant
below 60C
Resistant
Low, oxides
readily
Low, Crazes
readily
Resistant below
60C
Resistant
Low, oxides readily
Low, oxides readily
Low, Crazes readily
Low, Crazes readily
Resistant below 60C
Resistant below 60C
Resistant
Resistant
Oxidizing
Acids
Oxidizing Acids
Oxidizing Acids
Oxidizing Acids
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
10
Processing Properties of Polyethylene
Processing Properties
Branched Low
Density
Tmelt
98 – 115 C
Recommended Temp
I: 300F – 450F
Range
E: 250F – 450F
(I:Injection, E:Extrusion)
Molding Pressure
5 – 15 psi
Mold (linear) shrinkage
(in/in)
0.015 – 0.050
Medium Density
Linear High Density
122 – 124 C
High
Density
130 – 137 C
I: 300F – 450F
E: 250F – 450F
I: 350F – 500F
E: 350F – 525F
I: 350F – 500F
E: 350F – 525F
5 – 15 psi
12 – 15 psi
12– 15 psi
0.015 – 0.050
0.015 – 0.040
130 –137 C
0.015 – 0.040
11
Special Low Versions of Polyethylene
Produced through catalyst selection and regulation of reactor conditions
• Very Low Density Polyethylene (VLDPE)
• Densities between 0.890 and 0.915
• Applications include disposable gloves, shrink packages, vacuum cleaner
hoses, tuning, bottles, shrink wrap, diaper film liners, and other health care
products
• Linear Low Density Polyethylene (LLDPE)
• Densities between 0.916 and 0.930
• Contains little if any branching by co-polymerizing ethylene at low pressures
in presence of catalysts with small amounts of -olefin co-monomers
(butene, hexene, octene) which play the role of uniform short branches along
linear backbone.
• Properties include improved flex life, low warpage, improved stress-crack
resistance, better impact, tear, or puncture versus conventional LDPE
• Applications include films for ice, trash, garment, and produce bags at
thinner gage.
12
Special High Versions of Polyethylene
Produced through catalyst selection and regulation of reactor conditions
• Ultra High Molecular Weight Polyethylene (UHMWPE)
–
–
–
–
Extremely high MW at least 10 times of HDPE (MW=3M to 6M)
Process leads to linear molecules with HDPE
Densities are 0.93 to 0.94 g/cc and Moderate cost
High MW leads to high degree of physical entanglements that
• Above Tmelt (130 C or 266F), the material behaves in a rubber-like
molecule rather than fluid-like manner causing processing troubles,
high viscosities
• Processed similar to PTFE (Teflon)
– Ram extrusion and compression molding are used.
13
Special High Versions of Polyethylene
Produced through catalyst selection and regulation of reactor conditions
• Ultra High Molecular Weight Polyethylene (UHMWPE)
– Properties include outstanding properties like engineering plastic
or specialty resin
• Chemical inertness is unmatched; environmental stress cracking
resistance and resistance to foods and physiological fluids,
• Outstanding wear or abrasion resistance, very low coefficient of
friction, excellent toughness and impact resistance.
– Applications:
• pump parts, seals, surgical implants, pen tips, and butcher-block
cutting surfaces. , chemical handling equipment, pen tips, prosthetic
wear surfaces, gears
14
Special Forms of Polyethylene
• Cross-linked PE (XLPE)
– Chemical cross-links improve chemical resistance and improve
temperature properties.
– Cross-linked with addition of small amounts of organic peroxides
• Dicumyl peroxide, etc.
– Crosslinks a small amount during processing and then sets up after
flowing into mold.
– Used primarily with rotational molding
– Extruded Products
• Films (shrink wrap film in particular)
• Pipes
• Electrical wire and cable insulation
15
Copolymers of Polyethylene
• Ethylene-Vinyl Acetate (EVA)
– Repeating groups is ethylene with a vinyl acetate functional that reduces the
regularity of the chain; thus the crystallinity and stiffness
– Part of the pendent group are highly polar which makes film with increased water
vapor permeability, increased oil resistance and cling.
– Vinyl acetate reduces crystallinity and increases chemical reactivity because of hig
regions of polarity.
– Applications include flexible packaging, shrink wrap, auto bumper pads, flexible
toys, and tubing with vinylacetate up to 50%
H
H
H
H
C
C
C
C
H
H
H
O
m
C=O
C
n
16
Copolymers of Polyethylene
• Ethylene-vinyl alcohol (EVOH)
• Contains equal amounts of two repeat units that act as
– Barrier layers or as interlayers (tie layers) between incompatible
materials due to strong bonding of vinylalcohol repeat units.
• Ethylene-ethyl acrylate (EEA) Ethylene-methyl acrylate (EMA)
• Properties range from rubbery to tough ethylene-like properties
• Applications include hot melt adhesives, shrink wrap, produce bags,
bag-in-box products, and wire coating.
• Produced by addition of methyl acrylate monomer (40% by weight)
with ethylene gas
– reduces crystallinity and increases polarity
• Tough, thermally stable olefin with good rubber characteristics.
• Applications include food packaging, disposable medical gloves,
heat-sealable layers, and coating for composite packaging
17
•
Copolymers
of
Polyethylene
Ethylene-carboxylic acid (EAA, EMAA)
– Small amounts of acrylic acid (AA) or methacrylic acid (MAA) that feature
carboxyl acid groups (COOH) are notable adhesives, especially to polar
substrates, including fillers and reinforcements
– Problems include tackiness and corrosive to metals and crosslinking nature
• Ionomers
– Modified ethylene-methacrylic acid copolymers where some of the carboxyl
acid groups are converted into corresponding metallic salts (metal metacrylate),
where the metals are sodium or zinc.
– Ionic bonds are formed between these cationic and the remaining anionic acid
groups. Results in a quasi crosslinked polymer at low temperature and is
reversible at high temperature
– Useful properties, e.g., adhesive and paints to metals (polarity), resistance to
fats and oils, Flex, puncture, impact resistance
– Applications: golf balls, bowling pin covers, ski boot shells, films
18
Copolymers of Polyethylene
• Ethylene-Propylene (EPM)
– Ethylene and propylene are copolymerized in random manner and causes a delay
in the crystallization.
– Thus, the copolymer is rubbery at room temp because the Tg is between HDPE
(-110C) and PP (-20C).
– Ethylene and propylene can be copolymerized with small amounts of a
monomer containing 2 C=C double bonds (dienes)
– Results in a co-polymer, EPR, or thermoplastic rubber, TPR
H
H
H
H
C
C
C
C
H
H
CH3
H
n
19
m
Mechanical Properties of PE Blends
Mechanical Properties of PE Blends
Ethylene-vinyl
Ethylene-vinyl
acetate
alcohol
Density
0.922 – 0.943
1.14 – 1.19
Tensile
Strength, psi
Tensile
Modulus, psi
Tensile
Elongation, %
Impact Strength
Ethyleneethyl acrylate
0.93
Ethylene-methyl
acrylate
0.942 – 0.945
2,200 – 4,000
8,520 – 11,600
1,600 – 2,100 1,650
7K – 29K
300 K – 385 K
4K – 7.5 K
300% - 750%
180%- 280%
700% - 750% 740%
No break
1.0 – 1.7
No break
12 K
ft-lb/in
Hardness, Shore D17 – D45
D27 – D38
20
Processing Properties of PE Blends
Processing Properties
Ethylene-vinyl
acetate
Tmelt
103 – 108 C
Recommended Temp
C: 200-300F
Range (C: Compression) I: 300F – 430F
(I:Injection, E:Extrusion) E: 300F – 380F
Molding Pressure
1 – 20 psi
Mold (linear) shrinkage
(in/in)
0.007 – 0.035
Ethylene-vinyl
alcohol
142 – 181 C
Ethylene-ethyl
acrylate
Ethylene-methyl
acrylate
83 C
I: 365F – 480F
E: 365F – 480F
C: 200 – 300F
I: 250F – 500F
E: 300F – 620F
1 – 20 psi
0.015 – 0.035
21
Polypropylene History
• Prior to 1954 most attempts to produce plastics from
polyolefins had little commercial success
– PP invented in 1955 by Italian Scientist F.J. Natta by addition
reaction of propylene gas with a sterospecific catalyst titanium
trichloride.
– Isotactic polypropylene was sterospecific (molecules are
arranged in a definite order in space)
– PP is not prone to environmental stress-cracking like PE
• Polypropylene is similar in manufacturing method and in
properties to PE
• Tg of PP = -25C versus Tg of PE of -100C
22
Chemical Structure
• Propylene
H
H
C
C
CH3
H
n
• Isotactic- CH3 on one side of polymer chain (isolated).
Commercial PP is 90% to 95% Isotactic
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
C
C
C
C
C
CH3 H
CH3 H
CH3 H
CH3 H
CH3 H
23
Polypropylene Stereostatic Arrangements
•Atactic- CH3 in a random order (A- without; Tactic- order) Rubbery and of
limited commercial value.
H
H
H
CH3
H
CH3
H
H
H
CH3
C
C
C
C
C
C
C
C
C
C
CH3 H
H
H
H
H
CH3 H
H
H
•Syndiotactic- CH3 in a alternating order (Syndio- ; Tactic- order)
H
H
H
CH3
H
H
H
CH3
H
H
C
C
C
C
C
C
C
C
C
C
CH3 H
H
H
CH3 H
H
H
CH3 H
24
Addition Polymerization of PP
• Polypropylene produced with low pressure process (Ziegler)
• Polypropylene produced with linear chains
• Polypropylene is similar in manufacturing method and in properties to
PE
• Differences between PP and PE are
– Density: PP = 0.90; PE = 0.941 to 0.965
– Melt Temperature: PP = 176 C; PE = 110 C
– Tg of PP = -25C versus Tg of PE of -100C
– Service Temperature: PP has higher service temperature
– Hardness: PP is harder, more rigid, and higher brittle point
– Stress Cracking: PP is more resistant to environmental stress cracking
25
Advantages/Disadvatages of Polypropylene
• Advantages
–
–
–
–
–
–
–
–
–
–
Low Cost
Excellent flexural strength
Good impact strength
Processable by all thermoplastic
equipment
Low coefficient of friction
Excellent electrical insulation
Good fatigue resistance
Excellent moisture resistance
Service Temperature to 126 C
Very good chemical resistance
• Disadvantages
–
–
–
–
High thermal expansion
UV degradation
Poor weathering resistance
Subject to attack by chlorinated
solvents and aromatics
– Difficulty to bond or paint
– Oxidizes readily
– flammable
26
Mechanical Properties of Polypropylene
Mechanical Properties of Polypropylene
HDPE
Polypropylene LDPE
(For Comparison) (For Comparison)
0.90
0.91- 0.925
0.959-0.965
Density
Crystallinity
30% to 50%
30% to 50%
80% to 91%
10K to 30K
250K to 1.5M
Range of
MWD for
processing
4,500 – 5,500
Range of MWD
for processing
Range of MWD
for processing
600 - 2,300
5,000 – 6,000
165K – 225K
25K – 41K
150K – 158 K
100% - 600%
100% - 650%
10% - 1300%
0.4 – 1.2
No break
0.4 – 4.0
R80 - 102
D44 – D50
D66 – D73
Molecular Weight 200K to 600K
Molecular Weight
Dispersity MWD
(Mw/Mn)
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
ft-lb/in
Hardness, Shore
27
Physical Properties of Polyethylene
Physical Properties of Polypropylene
HDPE
Polypropylene LDPE
Transparent to Transparent to
Transparent to opaque
Optical
opaque
opaque
175 C
98 – 115 C
130 –137 C
Tmelt
Tg
H2 0
Absorption
-20 C
0.01 – 0.03
Low, oxides
Oxidation
readily
Resistance
UV Resistance Low, Crazes
readily
Resistant
Solvent
below 80C
Resistance
Resistant
Alkaline
Resistance
Oxidizing
Acid
Acids
Resistance
-100 C
Low < 0.01
-100 C
Low < 0.01
Low, oxides
readily
Low, Crazes
readily
Resistant below
60C
Resistant
Low, oxides readily
Oxidizing Acids
Oxidizing Acids
Low, Crazes readily
Resistant below 60C
Resistant
28
Processing Properties of Polyethylene
Processing Properties
Polypropylene
Tmelt
175 C
Recommended Temp
I: 400F – 550F
Range
E: 400F – 500F
(I:Injection, E:Extrusion)
Molding Pressure
10 -20 psi
Mold (linear) shrinkage
(in/in)
0.010 – 0.025
LDPE
98 – 115 C
HDPE
130 –137 C
I: 300F – 450F
E: 250F – 450F
I: 350F – 500F
E: 350F – 525F
5 – 15 psi
12– 15 psi
0.015 – 0.050
0.015 – 0.040
29
Several Olefin Polymers
• Polybutylene (PB)
–
–
–
–
–
–
• Polymethylpentene (PMP)
Based on butene-1 monomer
Plus comonomers (small amt)
Melt Point 125C similar to PE
Tg, -25C is closer to PP
Good creep & ESC resistance
Good for pipe and film extrusions
H
C
H
C
C2H5 H
H
H
C
C
HCH H
n
H3C C CH3
–
–
–
–
–
–
–
–
–
–
–
Trade name is TPX
Crystallizes to high degree (60%)
Highly transparent (90% transmis)
Properties similar to PP
Density is 0.83 g/cc, Tg =30C
Stable to 200C, Tm=240C
Creep and chemical resistance is good
and low permeability.
Electrical properties are excellent
Process by injection & extrusion
Good for lighting, packaging, trays,
bags, coffee makers, wire covering,
connectors, syringes.
Poor ESC and UV
n
30
H
Polyolefin_Polybutylene
• History
– PB invented in 1974 by Witco Chemical
– Ethyl side groups in a linear backbone
• Description
– Linear isotactic material
– Upon cooling the crystallinity is 30%
– Post-forming techniques can increase crystallinity to 55%
– Formed by conventional thermoplastic techniques
• Applications (primarily pipe and film areas)
– High performance films
– Tank liners and pipes
– Hot-melt adhesive
– Coextruded as moisture barrier and heat-sealable packages
H
H
C
C
CH2
H
CH3
31
Properties of Polybutylene
Mechanical Properties of Polybutylene
Polybutylene Polypropylene LDPE
HDPE
(For Comparison) (For Comparison)
0.908 -.917
0.90
0.91- 0.925
0.959-0.965
Density
Crystallinity
30% to 50%
30% to 50%
30% to 50%
80% to 91%
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
4,000
4,500 – 5,500
600 - 2,300
5,000 – 6,000
10K – 40K
165K – 225K
25K – 41K
150K – 158 K
300% - 400%
100% - 600%
100% - 650%
10% - 1300%
No break
0.4 – 1.2
No break
0.4 – 4.0
D44 – D50
D66 – D73
ft-lb/in
Hardness
Shore D55 – D65 R80 - 102
32
Polyolefin_Polymethylpentene (PMP)
• Description
H H
– Crystallizes to 40%-60%
– Highly transparent with 90% transmission
C C
– Formed by injection molding and blow molding
• Properties
CH2 H
– Low density of 0.83 g/cc; High transparency
H C-CH-CH
– Mechanical properties comparable to polyolefins with higher3 temperature3
properties and higher creep properties.
– Low permeability to gasses and better chemical resistance
– Attacked by oxidizing agents and light hydrogen carbon solvents
– Attacked by UV and is quite flammable
• Applications
– Lighting elements (Diffusers, lenses reflectors), liquid level
– Food packaging containers, trays, and bags.
33
Properties of Polymethylpentene
Mechanical Properties of Polymethylpentene
Polymethyl- Polypropylene LDPE
HDPE
pentene
(For Comparison) (For Comparison)
0.83
0.90
0.91- 0.925
0.959-0.965
Density
Crystallinity
40% to60%
30% to 50%
30% to 50%
80% to 91%
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
4,000 – 5,000
4,500 – 5,500
600 - 2,300
5,000 – 6,000
160K – 200K
165K – 225K
25K – 41K
150K – 158 K
100% - 400%
100% - 600%
100% - 650%
10% - 1300%
0.4 – 1.0
0.4 – 1.2
No break
0.4 – 4.0
R80 – R100
R80 - 102
D44 – D50
D66 – D73
ft-lb/in
Hardness
34
PVC Background
• Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB
– Polyvinyls were invented in 1835 by French chemist V. Regnault when he
discovered a white residue could be synthesized from ethylene dichloride in an
alcohol solution. (Sunlight was catalyst)
– PVC was patented in 1933 by BF Goodrich Company in a process that
combined a plasticizer, tritolyl phosphate, with PVC compounds making it easily
moldable and processed.
– PVC is the leading plastic in Europe and second to PE in the US.
– PVC is made by suspension process (82%), by mass polymerization (10% ), or
by emulsion (8%)
– All PVC is produced by addition polymerization from the vinyl chloride
monomer in a head-to-tail alignment.
– PVC is amorphous with partially crystalline (syndiotactic) due to structural
irregularity increasing with the reaction temperature.
– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas
35
PVC and Vinyl Products
• Rigid-PVC
– Pipe for water delivery
– Pipe for structural yard and garden structures
• Plasticizer-PVC or Vinyl
–
–
–
–
Latex gloves
Latex clothing
Paints and Sealers
Signs
36
PVC and PS Chemical Structure
• Vinyl Groups (homopolymers produced by addition polymerization)
– PVC
- poly vinylidene
- polyvinylalcohol (PVOH)
chloride (PVDC)
H H
H H
H Cl
C C
C C
C C
H Cl
n
– polyvinyl acetate (PVAc)
H Cl
H OH n
-n
PolyStyrene (PS)
H H
H
H
C C
C
C
H OCOCH3
n
H
n
37
Mechanical Properties of Polyvinyls
Mechanical Properties
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
PVC (rigid)
1.30-1.58
PVC (Flexible)
1.16-1.35
PVB
1.05
PVDC
1.65-1.72
6,000 - 7,500
1,500 -3,500
500 - 3,000
3,500 - 5,000
350K – 600K
160K –240K
40% - 80%
200%-450%
150% - 450%
160% -240%
0.4 - 22
Range
Range
0.4 - 1
Shore D65-85
Shore A50-100
M60-65
50 -100
70-250
190
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT 264 psi
140 F -170F
130F -150F
38
Physical Properties of Polyvinyls
Optical
Tmelt
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
PVC (rigid)
Transparent
PVC (Flexible)
Transparent
PVB
Transparent
PVDC
Transparent
75 – 105 C
75 – 105 C
49
172C
75 -105C
75-105C
49
-15C
0.04-0.4% (24h)
0.15-0.75% (24h)
0.09-0.16% (24h)
0.1% (24h)
good
good
good
good
Poor
Poor
Poor
good
Soluble in
Acetone, and
Cyclohexanol.
Partially in
Toluene
Excellent
Soluble in
Acetone, and
Cyclohexanol.
Partially in
Toluene
Excellent
Dissolved in ketones
and esters
good
Excellent
good
good
good
good
good
$0.27
$0.27
$
$1.62
39
Processing Properties of Polyvinyls
Tmelt
Recommended Temp
Range
(I:Injection, E:Extrusion,
C: Compression)
Molding Pressure
Mold (linear) shrinkage
(in/in)
PVC (rigid)
75 – 105 C
PVC (Flexible)
75 – 105 C
I: 300F – 415F I: 320F – 385F
C: 285F-400F C: 285F - 350F
10-40 kpsi
8-25 kpsi
0.002 – 0.006
0.010 – 0.050
PVB
49
PVDC
172C
I: 250F – 340F
C: 280F-320F
I: 300F – 400F
C: 260F-350F
E: 300F-400F
0.5-3kpsi
5 - 30 kpsi
0.005 - 0.025
40
Vinylchloride Co-Polymers
• Chlorinated PVC (CPVC)
– Possible to chemically modify PVC by substituting Cl for H
– Cl content can be raised from 56.8% in PVC to 62%-72%
– CPVC has improved chemical and temperature resistance that can be used for
pipe and hot water applications, even boiling water.
• Vinylchloride-vinylacetate (PVC-VAC)
– Internally plasticizing PVC with 3% to 30% vinyl acetate
– Impact properties and processing ease are improved for
• Floor coverings, phonograph records.
• Polyalloys
– Improves impact resistance of rigid PVC by blending with elastomers, e.g.,
EVA, Nitrile rubber (NBR), Chloronated PE.
– Blend PVC with PMMA and SAN for better transparency
– Blend PVC with ABS for improved combustion resistance
41
Vinylchloride Co-Polymers
H Cl
• Polyvinylidenechloride (PVDC)
C C
– Homopolymer can crystallize. Tg = -18C, Tm = 190C
H Cl n
• Decomposition temperature is slightly above melt temperature of abut 200C
• PVDC has outstanding barrier properties for O2, CO2, and H2O.
• Copolymerized with 10-15% vinyl chloride to create Saran Wrap.
• Copolymerize with acrlonitrile and acrylate esters up to 50%.
• Coplymerization reduces crystallinity to 35-45% and the Tmelt ot 175C
• Polyvinyl acetate (PVAC)
– Not used as a plastic
• Noncrystallizing
• Low Tg = 30C, it is
H H
C C
H OCOCH3 n
– It is best as a major ingredient in adhesives and paint, Elmers Glue
– Vinylacetate repeat units form the minor component in imporant copolymers
with vinylchloride (PVC-PVAC) and ethylene (EVA)
42
Vinylchloride Co-Polymers
• Polyvinylalcohol (PVAL or PVOH)
–
–
–
–
Homopolymer is very polar can crystallize
Water soluable. Tg = 80C, Tm = 240C
Random copolymer that is derived from PVAC
Used as a release film for reinforced plastics or barrier film.
H H
C C
H OH n
• Polyvinylbutyral (PVB)
– Random copolymer (PVB-PVAL)
H H
• containing 10-15% VAL
• Low Tg = 50C
C C
– Used in plasticized form as adhesive interlayer
H CH2
• For windshield safety glass (Saflex from Monsanto)
n
CH
• Powder is extruded into sheet and then placed between two layers of
2 glass
CH3
– Requires
• Toughness, transparency, weatherability, and adhesion to glass.
43
PS Background
• PS is one of the oldest known vinyl compounds
– PS was produced in 1851 by French chemist M. Berthelot by passing benzene and
ethylene through a red-hot-tube (basis for today)
– Amorphous polymer made from addition polymerization of styrene
– Homopolymer (crystal): (2.7 M metric tons in ’94) GPPS (General Purpose PS)
• Clear and colorless with excellent optical properties and high stiffness.
• It is brittle until biaxially oriented when it becomes flexible and durable.
– Graft copolymer or blend with elastomers- High Impact Polystyrene (HIPS):
• Tough, white or clear in color, and easily extruded or molded.
• Properties are dependent upon the elastomer %, but are grouped into
– medium impact (Izod<1.5 ft-lb), high impact (Izod between 1.5 to 2.4
ft-lb) and super-high impact (Izod between 2.6 and 5 ft-lb)
– Copolymers include SAN (poly styrene-acrylonitrile), SMA (maleic anhydride), SBS
(butadiene), styrene and acrylic copolymers.
– Expandable PS (EPS) is very popular for cups and insulation foam.
• EPS is made with blowing agents, such as pentane and isopentane.
• The properties are dependent upon cell size and cell size distribution
44
Polystyrene Polymers
H H
C
• Poly-para-methyl-styrene (PPMS)
C
H
CH3
– Similar to PS (Tg=100C) with a slightly higher Tg=110C
– Low cost alternative to PS in homo and co-polymers
n
• Poly-alpha-methyl-styrene (PAMS)
– High Tg =160C and better Temp resistance
– Not much commercial importance by itself
– Has significant use in copolymers
• Rubber-toughened impact polystyrene (HIPS)
H CH3
C
C
H
– Random copolymerization with small fraction of elastomer type repeat units.
Lowers Tg
– Block copolymerization of elastomeric component is more expensive, but keeps
Tg same as PS
45
n
PSB, SAN, ABS Chemical Structure
• PSB (copolymer -addition)
* Styrene- acrylonitrile (SAN)
H H
H H
H H
H H
C C
C C
C C
C C
H
CH3CH3
H
H C:::N
k
k
m
n
• ABS acrylonitrile butadiene styrene (Terpolymer- addition)
H H
H
H
H H
C C
C
C
C C
H C:::N
CH3 CH3
n
46
H
m
k
Polystyrene Co-Polymers
• Styrene-Butadiene (PSB)
– Tg= % of each PS (100C) and Butadiene (-80C)
• Example, 50% PS and 50% B, Tg=10C
– Easy to copolymerize and can be rubbery (butadiene-dominant) or plastic like
(styrene-like), out 70% of the PSB is styrene dominant
– Random (styrene dominant) copolymers have been used in emulsion (latex)
form to produce coatings (paints).
– Block copolymers are commercial butadiene styrene-plastics
• Styrene Acrylonitrile (SAN)
– Random copolymer of 30% polyacrylonitrile repeat units yields
• Increased Temp performance and transparent, ease to process
• Resistant to food and body oils
– Used for transparent medical products, houseware care items
– Polyalloys (blends) with polysulphone
47
Polystyrene Co-Polymers
• Acrylonitrile Butadiene Styrene (ABS)
– First introduced in the late 1940s as replacement for rubber.
– Terpolymer: Three repeat units vary according to grade (20%A, 20%B, 60%S)
• Acrylonitrile for chemical and temperature resistance
• Butadiene for impact resistance; Styrene for cost and processability
• Graft polymerization techniques are used to produce ABS
– Very versatile applications that are injection molded and extruded
• Rigid pipes and fittings, thermoformed refrigerator door liners, Legos toys
• Small boat hulls, telephone and computer housings
• Family of materials that vary from high gloss to low matte finish, and
from low to high impact resistance.
• Additives enable ABS grades that are flame retardant, transparent,
high heat-resistance, foamable, or UV-stabilized
• ABS-based polyalloys (blends)
– PVC/ABS for flame resistance
– TPU/ABS for polyurethane; PSU/ABS for polysulphone
– PC/ABS for temperature and impact resistance (Saturn door)
48
Mechanical Properties of PS, ABS, SAN
Mechanical Properties
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
PS
1.04
ABS
1.16-1.21
SAN
1.07
H
H
5,000 - 7,200
3,300 - 8,000
10,000 -12,000
C
C
330K-475K
320K-400K
475K-560K
1.2% - 2.5%
1.5%-25%
2%-3%
0.35-0.45
1.4-12
0.4-0.6
M60-75
R100-120
R83, M80
50 -83
65- 95
65-68
169F - 202F
190F - 225F
214F - 220F
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT
264 psi
H
n
Tg =100C
49
Physical Properties of PS, ABS, SAN
PS
Transparent
ABS
Transparent
SAN
Transparent
100 C
125C
120C
70 -115C
110 -125C
120C
0.01-0.03% (24h)
0.2-0.6% (24h)
0.15-0.25% (24h)
good
good
good
fair
fair
fair
Solvent
Resistance
Soluble in
Acetone, Benzene,
Toluene and
Methylene
dichloride
Dissolved in ketones
and esters
Alkaline
Resistance
Acid
Resistance
Excellent
Soluble in
Toluene and
Ethylene
dichloride,
Partially in
Benzene
Excellent
Poor: attacked by
oxidizing agents
Poor: attacked by
oxidizing agents
$0.41
$0.90
Optical
Tmelt
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Cost $/lb
Poor: attacked by
oxidizing agents
good
$0.87
50
Processing Properties of PS, ABS, SAN
Tmelt
Recommended Temp
Range
(I:Injection, E:Extrusion)
Molding Pressure
Mold (linear) shrinkage
(in/in)
PS
100 C
ABS
125C
SAN
120C
I: 350F – 500F
E: 350F- 500F
C: 300F - 400F
I: 380F – 500F
C: 350F - 500F
I: 360F – 550F
E: 360F -450F
C:300F - 400F
5 - 20 kpsi
8-25 kpsi
5-20 kpsi
0.004 – 0.007
0.004 – 0.008
0.003 – 0.005
51
Acrylic and Cellulosic Background
• Acrylics (1901)
– Includes acrylic and methacrylic esters, acids, and derivatives.
– Used singularly or in combination with other polymers to produce
products ranging from soft, flexible elastomers to hard, stiff
thermoplastics and thermosets.
• Cellulosics (1883)
– Cellulose nitrate was first developed in the 1880s.
– First uses were billiard balls, combs, and photographic film.
– Cellulose acetate was developed in 1927 reduced the limitations of
flammability, and solvent requirement.
– In 1923, CA became the first material to be injection molded.
– Cellulose acetate butyrate (CAB) in1938 and Cellulose acetate
propionate (CAP) in 1945 found applications for hair brushes,
52
toothbrushes, combs, cosmetic cases, hand tool handles, steering
Acrylics Chemical Structure
• Acrylics- Basic formula
- Polymethyl acrylate
H R1
H H
C C
C C
H COOR2
H COOCH3
n
• Polymethyl methacrylate
n
H CH3
-AcrylateStyreneAcrylonitrile (ASA)
H H
H H
H H
C C
C C
C C
C C
H COOCH3
H COOH
H
H C:::N
n
n
m
53
k
Applications for PC and Acrylics
• PC (high impact strength, transparency, excellent creep and
temperature)
– lenses, films, windshields, light fixtures, containers, appliance
components and tool housings
– hot dish handles, coffee pots, popcorn popper lids, hair dryers.
– Pump impellers, safety helmets, beverage dispensers, trays, signs
– aircraft parts, films, cameras, packaging
• Acrylics
– Optical applications, outdoor advertising signs, aircraft windshields,
cockpit covers, bubble bodies for helicopters
– Plexiglass, window frames, (glass filled): tubs, counters, vanities
54
Mechanical Properties of Acrylic, PC,
PC/ABS
Mechanical Properties
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
Acrylic
1.16- 1.19
PC
1.2
ABS
1.16-1.21
PC/ABS
1.07 - 1.15
5,000 - 9,000
9,500
3,300 - 8,000
5,800 - 9,300
200K – 500K
350 K
320K-400K
350K -450K
20 - 70%
110%
1.5%-25%
50%-60%
0.65 -2.5
16
1.4-12
6.4 - 11
M38-M68
M70
R100-120
R95 -R120
48 - 80
68
65- 95
67
165-209F
270
190F - 225F
225F
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT 264 psi
55
Physical Properties of Acrylic, PC, PC/ABS
Optical
Tmelt
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
Acrylic
Transparent
PC
Transparent
ABS
Transparent
PC/ABS
Transparent
105C
150C
125C
135C
75 -105C
110 -125C
110 -125C
120C
0.01-0.03% (24h)
0.2-0.6% (24h)
0.2-0.6% (24h)
0.15-0.25% (24h)
good
good
good
good
fair
fair
fair
fair
Soluble in
Acetone, Benzene,
Toluene, ethylene
dichloride
Excellent
Partially Soluble in
Acetone, Benzene,
Toluene. Dissolves in
hot benzene-toluene
Excellent
Poor: attacked by
oxidizing agents
Poor: attacked by
oxidizing agents
$0.41
$0.90
Soluble in Toluene
Soluble in Toluene
and Ethylene
and Ethylene
dichloride, Partially in dichloride, Partially in
Benzene
Benzene
Excellent
Poor: attacked by
oxidizing agents
Poor: attacked by
good
oxidizing agents
$0.90
$0.87
56
Advantages
• PC
– High impact strength, excellent creep resistance, transparent
– Very good dimensional stability and continuous temp over 120 C
• Acrylics
– Optical clarity, weatherability, electrical properties, rigid, high
gloss
Disadvantages
• PC
– High processing temp,UV degradation
– Poor resistance to alkalines and subject to solvent cracking
• Acrylics
– Poor solvent resistance, stress cracking, combustibility, Use T
57 93C
Polyamide History
• PA is considered the first engineering thermoplastic
• PA is one of many heterochain thermoplastics, which has
atoms other than C in the chain.
• PA invented in 1928 by Wallace Carothers, DuPont, in
search of a “super polyester” fiber with molecular weights
greater than 10,000. First commercial nylon in 1938.
• PA was created when a condensation reaction occurred
between amino acids, dibasic acids, and diamines.
• Nylons are described by a numbering system which
indicates the number of carbon atoms in the monomer
chains
– Amino acid polymers are designated by a single number, as nylon
58
6
Chemistry & Chemical Structure
• Thermoplastic nylonslinear
havepolyamides
amide (CONH) repeating link
• Nylon 6,6 - poly-hexamethylene-diamine (linear)
NH2(CH2)6NH2 + COOH(CH2)4COOH
hexamethylene diamine + Adipic Acid
n[NH2(CH2)6NH . CO (CH2)4COOH ] + (heat)
nylon salt
[NH2(CH2)6NH . CO (CH2)4CO ]n + nH2O
Nylon 6,6 polymer chain
• Nylon 6 - polycaprolactam (linear)
[NH(CH2)5CO ]n
59
Chemistry & Chemical Structure
linear polyamides
• Nylon 6, 10 - polyhexamethylenesebacamide (linear)
[NH2(CH2)6NH . CO (CH2)8CO]n
• Nylon 11 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)10CO ]n
• Nylon 12 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)11CO ]n
• Other Nylons
– Nylon 8, 9, 46, and copolymers from other diamines and acids
60
Chemistry & Chemical Structure
Aromatic polyamides (aramids)
• PMPI - poly m-phenylene isophthalamide (LCP fiber)
[
-NHCO NHCO ]n
• PPPT - poly p-phenylene terephthalamide (LCP fiber)
[
-NHCO NHCO ]n
• Nomax PMPI – first commercial aramid fiber for electrical insulation. LCP
fibers feature straight chain crystals
• Kevlar 29 PPPT– textile fiber for tire cord, ropes, cables etc.
61
• Kevlar 49 PPPT - reinforcing fiber for thermosetting resins
Chemistry & Chemical Structure
Transparent polyamides
• PA- (6,3,T)
[CH2C3H6C2H4-NHCO -
NHCO ]n
• PA - (6,T)
[(CH2) 6NHCO -
NHCO ]n
• Transparent polyamides are commercially available
• Reduced crystallization due to introduction of side
groups
62
Applications for Polyamides
• Fiber applications
– 50% into tire cords (nylon 6 and nylon 6,6)
– rope, thread, cord,belts, and filter cloths.
– Monofilaments- brushes, sports equipment, and bristles (nylon 6,10)
• Plastics applications
–
–
–
–
bearings, gears, cams
rollers, slides, door latches, thread guides
clothing, light tents, shower curtains, umbrellas
electrical wire jackets (nylon 11)
• Adhesive applications
– hot melt or solution type
– thermoset reacting with epoxy or phenolic resins
– flexible adhesives for bread wrappers, dried soup packets,
63
Mechanical Properties of Polyamides
Mechanical Properties of Nylon
Nylon 6
1.13-1.15
Density, g/cc
Nylon 6,6
1.13-1.15
Nylon 6,10
1.09
Nylon 6,12
1.06-1.10
30-% - 50%
30-% - 50%
30-% - 50%
30-% - 50%
Molecular Weight
10,000–30,000
10,000–30,000
10,000–30,000
10,000–30,000
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
6,000 – 24,000
14,000
8,500 – 8,600
6,500 – 8,800
300K
230K – 550K
250 K
220 - 290 K
30% - 100%
15%-80%
70%
150%
0.6 – 2.2
0.55 – 1.0
1.2
1.0 –1.9
R80 - 102
R120
R111
M78
Crystallinity
ft-lb/in
Hardness
64
Physical Properties of Polyamide
Optical
Tmelt
Nylon 6
Translucent to
opaque
210C -220 C
Nylon 6,6
Translucent to
opaque
255C – 265C
Nylon 6,10
Translucent to opaque
Nylon 6,12
Translucent to opaque
220 C
195 -219 C
1.3-1.9% (24h)
8.5-10 (Max)
1.0-2.8% (24h)
8.5% (Max)
1.4% (24h)
3.3% (Max)
0.4 – 1.0% (24h)
2.5 –3 % (Max)
good
good
good
good
Poor
Poor
Poor
Poor
Dissolved by
phenol &
formic acid
Resistant
Dissolved by
phenol & formic
acid
Resistant
Dissolved by phenol &
formic acid
Dissolved by phenol &
formic acid
Resistant
Resistant
Poor
Poor
Poor
Poor
$1.30
$1.30
$3.00
$3.10
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
65
Advantages Disadvantages of Polyamide
• Advantages
–
–
–
–
–
–
–
Tough, strong, impact resistant
Low coefficient of friction
Abrasion resistance
High temperature resistance
Processable by thermopalstic methods
Good solvent resistance
Resistant to bases
• Disadvantages
– High moisture absorption with dimensional instability
• loss of up to 30 % of tensile strength and 50% of tensile modulus
–
–
–
–
–
Subject to attack by strong acids and oxidizing agents
Requires UV stabilization
High shrinkage in molded sections
Electrical and mechanical properties influenced by moisture content
Dissolved by phenols
66
Additives and Reinforcements to PA
• Additives- antioxidants, UV stabilizers, colorants, lubricants
• Fillers
– Talc
– Calcium carbonate
• Reinforcements
–
–
–
–
–
–
Glass fiber- short fiber (1/8” or long fiber 1/4”)
Mineral fiber (wolastonite)
carbon fibers
graphite fibers
metallic flakes
steel fibers
67
Properties of Reinforced Nylon
Nylon 6,6
Density, g/cc
1.13-1.15
Nylon 6,6 with
30% short glass
1.4
Nylon 6,6 with
30% long glass
1.4
Nylon 6,6 with
30% carbon fiber
1.06-1.10
Crystallinity
30-% - 50%
30-% - 50%
30-% - 50%
30-% - 50%
Molecular Weight
10,000–30,000
30,000
10,000–30,000
10,000–30,000
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
14,000
28,000
28,000
32,000
230K – 550K
1,300K
1,400 K
3,300 K
15%-80%
3%
3%
4%
0.55 – 1.0
1.6-4.5
4.0
1.5
R120
R120
E60
R120
1.0-2.8% (24h)
8.5% (Max)
0.7-1.1 (24h)
5.5-6.5 (Max)
0.9 (24h)
5.5-6.5 (Max)
0.7 (24h)
5 (Max)
$1.40
$1.70
$2.00
ft-lb/in
Hardness
Moisture %
Cost $/lb
$2.70 68
Other Heterochain Polymers
O
C
O
C
N
• Polyimide
N
C
O
C
– Developed by Du Pont in 1962
– Obtained from a condensation polymerization of aromatic diamine
and an aromatic dianhydride
– Characterized as Linear thermoplastics that are difficult to process
– Many polyimides do not melt but are fabricated by machining
– Molding can occur if enough time for flow is allowed for T>Tg
• Advantages
– High temperature service (up to 700C)
– Excellent barrier, electrical properties, solvent and wear resistance
69
– Good adhesion and ezpecially suited for composite fabrication
Other Heterochain Polymers
• Polyimide Disadvantages
– Difficulty to fabricate and requires venting of volatiles
– Hydroscopic and Subject to attacks by alkalines
– Comparatively high cost
• Applications
• Aerospace, electronics, and nuclear uses (versus flurocarbons)
• Office and industrial equipment; Laminates, dielectrics, and coatings
• Valve seats, gaskets, piston rings, thrust washers, and bushings
• Polyamide-imide
• Amorphous member of imide family, marketed in 1972 (Torlon), and
used in aerospace applications such as jet engine components
• Contains aromatic rings and nitrogen linkage
• Advantages include: High temperature properties (500F), low
70
coefficient of friction, and dimensional stability.
Other Heterochain Polymers
H-O-(CH2-O-CH2-O)NH:R
• Polyacetal or Polyoxymethylene (POM)
• Polymerized from formaldehyde gas
• First commercialized in 1960 by Du Pont
• Similar in properties to Nylon and used for plumbing fixtures, pump
impellers, conveyor belts, aerosol stem valves, VCR tape housings
• Advantages
• Easy to fabricate, has glossy molded surfaces, provide superior
fatigue endurance, creep resistance, stiffness, and water resistance.
• Among the strongest and stiffest thermoplastics.
• Resistant to most chemicals, stains, and organic solvents
• Disadvantages
• Poor resistance to acids and bases and difficult to bond
• Subject to UV degradation and is flammable
• Toxic fumes released upon degradation
71
Mechanical Properties
Density, g/cc
Nylon 6
1.13-1.15
Crystallinity
30-% - 50%
Acetal
1.42
Polyimid
1.43
Polyamide-imide
1.41
10,000
26,830
Molecular Weight
10,000–30,000
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
6,000 – 24,000
10,000
300K
520K
30% - 100%
40% - 75%
0.6 – 2.2
0.07
0.9
2.5
Hardness
R80 - 102
R120
E50
E78
Tmelt
Moisture
24 hr
max
Optical
210 - 220 C
1.3 - 1.9%
8.5 - 10%
175-181 C
0.25 to 0.40%
1.41%
0.32%
Tg=275C
.28%
Translucent to
opaque
Translucent to
opaque
ft-lb/in
opaque
Transparent to
opaque
72
Polyester History
• 1929 W. H. Carothers suggested classification of polymers
into two groups, condensation and addition polymers.
• Carothers was not successful in developing polyester fibers
from linear aliphatic polyesters due to low melting point and
high solubility. No commercial polymer is based on these.
• p-phenylene group is added for stiffening and leads to
polymers with high melting points and good fiber-forming
properties, e.g., PET.
• Polymers used for films and for fibers
• Polyesters is one of many heterochain thermoplastics, which
has atoms other than C in the chain.
• Polyesters includes unsaturated (thermosets), saturated73 and
aromatic thermoplastic polyesters.
Chemistry & Chemical Structure
linear polyesters (versus branched)
O
• Thermoplastic polyesters have ester(-C-O) repeating link
• Polyester (linear) PET and PBT
C6H4(COOH)2 + (CH2)2(OH)2
O]terephthalic acid
+ ethylene glycol
O
-[(CH2)2 -O- C
terephthalic acid
+ butylene glycol
- C-
Polyethylene terephthalate (PET)
O
C6H4(COOH)2 + (CH2)4(OH)2
O]-
O
O
-[(CH2)4 -O- C
- C-
Polybutylene terephthalate (PBT)
74
Chemistry & Chemical Structure
linear polyesters (versus branched)
• Wholly aromatic copolyesters (LCP)
– High melting sintered: Oxybenzoyl (does not melt below its
decomposition temperature. Must be compression molded)
– Injection moldable grades: Xydar and Vectra
– Xydar (Amoco Performance Products)
• terephthalic acid, p,p’- dihydroxybiphenyl, and p-hydroxybenzoic
acid
– Grade 1: HDT of 610F
– Grade 2: HDT of 480 F
– Vectra (Hoechst Celanese Corp.)
• para-hydroxybenzoic acid and hydroxynaphtholic acid
– Contains rigid chains of long, flat monomer units which are thought to
75
undergo parallel ordering in the melt and form tightly packed fibrous
PET Chemical Structure and Applications
• The flexible, but short, (CH2)2 groups tend to leave the
chains relatively stiff and PET is notes for its very slow
crystallization. If cooled rapidly from the melt to a Temp
below Tg, PET solidifies in amorphous form.
• If PET is reheated above Tg, crystallizaiton takes place to
up to 30%.
• In many applications PET is first pre-shaped in
amorphous state and then given a uniaxial (fibers or
tapes) or biaxial (film or containers) crystalline
orientation.
• During Injection Molding PET can yield amorphous
transparent objects (Cold mold) or crystalline opaques
76
objects (hot mold)
PBT Chemical Structure and Applications
• The longer, more flexible (CH2)4 groups allow for more
rapid crystallization than PET.
• PBT is not as conveniently oriented as PET and is
normally injection molded.
• PBT has a sharp melting transition with a rather low melt
viscosity.
• PBT has rapid crystallization and high degree of
crystallization causing warpage concerns
77
Thermoplastic Aromatic Copolyesters
• Polyarylesters
– Repeat units feature only aromatic-type groups (phenyl or aryl
groups) between ester linkages.
– Called wholly aromatic polyesters
– Based on a combination of suitable chemicals
•
•
•
•
p-hydroxybenzoic acid
terephthalic acid
isophthalic acid,
bisphenol-A
– Properties correspond to a very stiff and regular chain with high
crystallinity and high temperature stability
– Applications include bearings, high temperature sensors, aerospace
applications
– Processed in injection molding and compression molding 78
– Most thermoplastic LCP appear to be aromatic copolyesters
Applications for Polyesters (PET)
• Blow molded bottles
• 100% of 2-liter beverage containers and liquid products
• Fiber applications
• 25% of market in tire cords, rope, thread, cord, belts, filter cloths.
• Monofilaments- brushes, sports equipment, clothing, carpet, bristles
• Tape form- uniaxially oriented tape form for strapping
• Film and sheets
• photographic and x-ray films; biaxial sheet for food packages
• Molded applications- Reinforced PET [Rynite, Valox, Impet]
• luggage racks, grille-opening panels, functional housings such as
windshield wiper motors, blade supports, and end bells
• sensors, lamp sockets, relays, switches, ballasts, terminal blocks
• Appliances and furniture
• oven and appliance handles, coil forms for microwaves
• panel pedestal bases, seat pans, chair arms, and casters
79
Applications for Polyesters (PBT and LCP)
• PBT - 30 M lbs in 1988
• Molded applications (PBT) [Valox, Xenoy, Vandar, Pocan]
– distributers, door panels, fenders, bumper fascias
– automotive cables, connectors, terminal blocks, fuse holders and
motor parts, distributor caps, door and window hardware
• Extruded applications
– extrusion-coat wire
– extruded forms and sheet produced with some difficulty
• Electronic Devices (LCP) [26 M lbs] [Terylene, Dacron, Kodel]
– fuses, oxygen and transmission sensors
– chemical process equipment and sensors
– coil
80
Mechanical Properties of Polyesters
Mechanical Properties of polyester
PET
1.29-1.40
Density, g/cc
Crystallinity
PBT
1.30 - 1.38
LCP Polyester
1.35 - 1.40
10% - 30%
60%
>80%
7,000 – 10,500
8,200
16,000 – 27,000
400K - 600K
280K – 435K
1,400K - 2,800K
30% - 300%
50%-300%
1.3%-4.5%
0.25 - 0.70
0.7 - 1.0
2.4 - 10
65
60-95
25-30
70F -100F
122F - 185F
356F -671F
Molecular Weight
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
ft-lb/in
CLTE
10-6 in/in/C
HDT
264 psi
81
Physical Properties of Polyester
Optical
Tmelt
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
PET
Transparent to
Opaque
245C -265 C
PBT
Opaque
LCP Polyester
Opaque
220C – 267C
400 C - 421 C
0.1 - 0.2% (24h)
0.085% (24h)
0.45% (Max)
<0.1% (24h)
<0.1% (Max)
good
good
good
Poor
Poor
none
Attacked by
halogen
hydrocarbons
Poor
good
good
Poor
Poor
Poor
Poor
fair
$0.53
$1.48
$7.00 - $10.00
73C - 80C
82
•
Advantages and Disadvantages of
Advantages
Polyesters
– Tough and rigid and PBT has low moisture absorption
– Processed by thermoplastic operations
– Recycled into useful products as basis for resins in such
applications as sailboats, shower units, and floor tiles
– PET flakes from PET bottles are in great demand for fiberfill for
pillows and sleeping bags, carpet fiber, geo-textiles, and regrind for
injection and sheet molding
• Disadvantages
–
–
–
–
Subject to attack by acids and bases
Low thermal resistance
Poor solvent resistance
Must be adequately dried in dehumidifier prior to processing to
83
prevent hydrolytic degradation.
Thermoplastic Copolyesters
• Copolyester is applied to those polyesters whose synthesis
uses more than one glycol and/or more than one dibasic
acid.
• Copolyester chain is less regular than monopolyester chain
and as a result has less crystallinity
• PCTA copolyester (Poly cyclo-hexane-dimethanolterephthalate acid) [amorphous]
– Reaction includes cyclohexanedimethanol and terephthalic acid
with another acid substituted for a portion of the terephthalic acid
– Extruded as transparent film or sheets that are suitable for
packaging applications (frozen meats shrink bags, blister packages,
etc..)
• Glycol-modified PET (PETG) [amorphous]
– Blow-molded containers, thermoformed blister packages.
84
ABS, PC Background
• ABS was invented during WWII as a replacement for rubber
– ABS is a terpolymer: acrylonitrile (chemical resistance), butadiene
(impact resistance), and styrene (rigidity and processing ease)
– Graft polymerization techniques are used to produce ABS
– Family of materials that vary from high gloss to low matte finish,
and from low to high impact resistance.
– Additives enable ABS grades that are flame retardant, transparent,
high heat-resistance, foamable, or UV-stabilized.
• PC was invented in 1898 by F. Bayer in Germany
– Commercial production began in the US in 1959.
– Amorphous, engineering thermoplastic that is known for
toughness, clarity, and high-heat deflection temperatures.
– Polycarbonates are linear, amorphous polyesters because they
contain esters of carbonic acid and an aromatic bisphenol. 85
Polyamide History
• PA is considered the first engineering thermoplastic
• PA is one of many heterochain thermoplastics, which has
atoms other than C in the chain.
• PA invented in 1928 by Wallace Carothers, DuPont, in
search of a “super polyester” fiber with molecular weights
greater than 10,000. First commercial nylon in 1938.
• PA was created when a condensation reaction occurred
between amino acids, dibasic acids, and diamines.
• Nylons are described by a numbering system which
indicates the number of carbon atoms in the monomer
chains
– Amino acid polymers are designated by a single number, as nylon
86
6
Chemistry & Chemical Structure
• Thermoplastic nylonslinear
havepolyamides
amide (CONH) repeating link
• Nylon 6,6 - poly-hexamethylene-diamine (linear)
NH2(CH2)6NH2 + COOH(CH2)4COOH
hexamethylene diamine + Adipic Acid
n[NH2(CH2)6NH . CO (CH2)4COOH ] + (heat)
nylon salt
[NH2(CH2)6NH . CO (CH2)4CO ]n + nH2O
Nylon 6,6 polymer chain
• Nylon 6 - polycaprolactam (linear)
[NH(CH2)5CO ]n
87
Chemistry & Chemical Structure
linear polyamides
• Nylon 6, 10 - polyhexamethylenesebacamide (linear)
[NH2(CH2)6NH . CO (CH2)8CO]n
• Nylon 11 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)10CO ]n
• Nylon 12 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)11CO ]n
• Other Nylons
– Nylon 8, 9, 46, and copolymers from other diamines and acids
88
Chemistry & Chemical Structure
Aromatic polyamides (aramids)
• PMPI - poly m-phenylene isophthalamide (LCP fiber)
[
-NHCO NHCO ]n
• PPPT - poly p-phenylene terephthalamide (LCP fiber)
[
-NHCO NHCO ]n
• Nomax PMPI - first commercial aramid fiber for
electrical insulation. LCP fibers feature straight chain
crystals
• Kevlar 29 PPPT- textile fiber for tire cord, ropes, cables89
Chemistry & Chemical Structure
Transparent polyamides
• PA- (6,3,T)
[CH2C3H6C2H4-NHCO -
NHCO ]n
• PA - (6,T)
[(CH2) 6NHCO -
NHCO ]n
• Transparent polyamides are commercially available
• Reduced crystallization due to introduction of side
groups
90
Applications for Polyamides
• Fiber applications
– 50% into tire cords (nylon 6 and nylon 6,6)
– rope, thread, cord,belts, and filter cloths.
– Monofilaments- brushes, sports equipment, and bristles (nylon 6,10)
• Plastics applications
–
–
–
–
bearings, gears, cams
rollers, slides, door latches, thread guides
clothing, light tents, shower curtains, umbrellas
electrical wire jackets (nylon 11)
• Adhesive applications
– hot melt or solution type
– thermoset reacting with epoxy or phenolic resins
– flexible adhesives for bread wrappers, dried soup packets,
91
Mechanical Properties of Polyamides
Mechanical Properties of Nylon
Nylon 6
1.13-1.15
Density, g/cc
Nylon 6,6
1.13-1.15
Nylon 6,10
1.09
Nylon 6,12
1.06-1.10
30-% - 50%
30-% - 50%
30-% - 50%
30-% - 50%
Molecular Weight
10,000–30,000
10,000–30,000
10,000–30,000
10,000–30,000
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
6,000 – 24,000
14,000
8,500 – 8,600
6,500 – 8,800
300K
230K – 550K
250 K
220 - 290 K
30% - 100%
15%-80%
70%
150%
0.6 – 2.2
0.55 – 1.0
1.2
1.0 –1.9
R80 - 102
R120
R111
M78
Crystallinity
ft-lb/in
Hardness
92
Physical Properties of Polyamide
Optical
Tmelt
Nylon 6
Translucent to
opaque
210C -220 C
Nylon 6,6
Translucent to
opaque
255C – 265C
Nylon 6,10
Translucent to opaque
Nylon 6,12
Translucent to opaque
220 C
195 -219 C
1.3-1.9% (24h)
8.5-10 (Max)
1.0-2.8% (24h)
8.5% (Max)
1.4% (24h)
3.3% (Max)
0.4 – 1.0% (24h)
2.5 –3 % (Max)
good
good
good
good
Poor
Poor
Poor
Poor
Dissolved by
phenol &
formic acid
Resistant
Dissolved by
phenol & formic
acid
Resistant
Dissolved by phenol &
formic acid
Dissolved by phenol &
formic acid
Resistant
Resistant
Poor
Poor
Poor
Poor
$1.30
$1.30
$3.00
$3.10
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
93
Advantages Disadvantages of Polyamide
• Advantages
–
–
–
–
–
–
–
Tough, strong, impact resistant
Low coefficient of friction
Abrasion resistance
High temperature resistance
Processable by thermopalstic methods
Good solvent resistance
Resistant to bases
• Disadvantages
– High moisture absorption with dimensional instability
• loss of up to 30 % of tensile strength and 50% of tensile modulus
–
–
–
–
Subject to attack by strong acids and oxidizing agents
Requires UV stabilization
High shrinkage in molded sections
Electrical and mechanical properties influenced by moisture content
94
Additives and Reinforcements to PA
• Additives- antioxidants, UV stabilizers, colorants, lubricants
• Fillers
– Talc
– Calcium carbonate
• Reinforcements
–
–
–
–
–
–
Glass fiber- short fiber (1/8” or long fiber 1/4”)
Mineral fiber (wolastonite)
carbon fibers
graphite fibers
metallic flakes
steel fibers
95
Properties of Reinforced Nylon
Nylon 6,6
Density, g/cc
1.13-1.15
Nylon 6,6 with
30% short glass
1.4
Nylon 6,6 with
30% long glass
1.4
Nylon 6,6 with
30% carbon fiber
1.06-1.10
Crystallinity
30-% - 50%
30-% - 50%
30-% - 50%
30-% - 50%
Molecular Weight
10,000–30,000
30,000
10,000–30,000
10,000–30,000
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
14,000
28,000
28,000
32,000
230K – 550K
1,300K
1,400 K
3,300 K
15%-80%
3%
3%
4%
0.55 – 1.0
1.6-4.5
4.0
1.5
R120
R120
E60
R120
1.0-2.8% (24h)
8.5% (Max)
0.7-1.1 (24h)
5.5-6.5 (Max)
0.9 (24h)
5.5-6.5 (Max)
0.7 (24h)
5 (Max)
$1.40
$1.70
$2.00
ft-lb/in
Hardness
Moisture %
Cost $/lb
$2.70 96
Other Heterochain Polymers
O
C
O
C
N
• Polyimide
N
C
O
C
– Developed by Du Pont in 1962
– Obtained from a condensation polymerization of aromatic diamine
and an aromatic dianhydride
– Characterized as Linear thermoplastics that are difficult to process
– Many polyimides do not melt but are fabricated by machining
– Molding can occur if enough time for flow is allowed for T>Tg
• Advantages
– High temperature service (up to 700C)
– Excellent barrier, electrical properties, solvent and wear resistance
97
– Good adhesion and ezpecially suited for composite fabrication
Other Heterochain Polymers
• Polyimide Disadvantages
–
–
–
–
Difficulty to fabricate and requires venting of volatiles
Hydroscopic
Subject to attacks by alkalines
Comparatively high cost
• Applications
– Aerospace, electronics, and nuclear uses (competes with
flurocarbons)
– Office and industrial equipment; Laminates, dielectrics, and
coatings
– Valve seats, gaskets, piston rings, thrust washers, and bushings
• Polyamide-imide
– Amorphous member of imide family, marketed in 1972 (Torlon),
98
and used in aerospace applications such as jet engine components
Other Heterochain Polymers
H-O-(CH2-O-CH2-O)NH:R
• Polyacetal or Polyoxymethylene (POM)
– Polymerized from formaldehyde gas
– First commercialized in 1960 by Du Pont
– Similar in properties to Nylon and used for plumbing fixtures,
pump impellers, conveyor belts, aerosol stem valves, VCR tape
housings
• Advantages
– Easy to fabricate, has glossy molded surfaces, provide superior
fatigue endurance, creep resistance, stiffness, and water resistance.
– Among the strongest and stiffest thermoplastics.
– Resistant to most chemicals, stains, and organic solvents
• Disadvantages
– Poor resistance to acids and bases and difficult to bond
99
Mechanical Properties
Density, g/cc
Nylon 6
1.13-1.15
Crystallinity
30-% - 50%
Acetal
1.42
Polyimid
1.43
Polyamide-imide
1.41
10,000
26,830
Molecular Weight
10,000–30,000
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
6,000 – 24,000
10,000
300K
520K
30% - 100%
40% - 75%
0.6 – 2.2
0.07
0.9
2.5
Hardness
R80 - 102
R120
E50
E78
Tmelt
Moisture
24 hr
max
Optical
210 - 220 C
1.3 - 1.9%
8.5 - 10%
175-181 C
0.25 to 0.40%
1.41%
0.32%
Tg=275C
.28%
Translucent to
opaque
Translucent to
opaque
ft-lb/in
opaque
Transparent to
opaque
100
Polyester History
• 1929 W. H. Carothers suggested classification of polymers
into two groups, condensation and addition polymers.
• Carothers was not successful in developing polyester fibers
from linear aliphatic polyesters due to low melting point and
high solubility. No commercial polymer is based on these.
• p-phenylene group is added for stiffening and leads to
polymers with high melting points and good fiber-forming
properties, e.g., PET.
• Polymers used for films and for fibers
• Polyesters is one of many heterochain thermoplastics, which
has atoms other than C in the chain.
• Polyesters includes unsaturated (thermosets), saturated
101 and
aromatic thermoplastic polyesters.
Chemistry & Chemical Structure
linear polyesters (versus branched)
O
• Thermoplastic polyesters have ester(-C-O) repeating link
O
O
• Polyester (linear) PET and PBT
C6H4(COOH)2 + (CH2)2(OH)2
O]terephthalic acid
+ ethylene glycol
-[(CH2)2 -O- C
- C-
Polyethylene terephthalate (PET)
O
O
C6H4(COOH)2 + (CH2)4(OH)2
O]terephthalic acid
+ butylene glycol
-[(CH2)4 -O- C
- C-
Polybutylene terephthalate (PBT)
102
Chemistry & Chemical Structure
linear polyesters (versus branched)
• Wholly aromatic copolyesters (LCP)
– High melting sintered: Oxybenzoyl (does not melt below its
decomposition temperature. Must be compression molded)
– Injection moldable grades: Xydar and Vectra
– Xydar (Amoco Performance Products)
• terephthalic acid, p,p’- dihydroxybiphenyl, and p-hydroxybenzoic
acid
– Grade 1: HDT of 610F
– Grade 2: HDT of 480 F
– Vectra (Hoechst Celanese Corp.)
• para-hydroxybenzoic acid and hydroxynaphtholic acid
– Contains rigid chains of long, flat monomer units which are thought to
103
undergo parallel ordering in the melt and form tightly packed fibrous
chains in molded parts.
PET Chemical Structure and Applications
• The flexible, but short, (CH2)2 groups tend to leave the
chains relatively stiff and PET is notes for its very slow
crystallization. If cooled rapidly from the melt to a Temp
below Tg, PET solidifies in amorphous form.
• If PET is reheated above Tg, crystallizaiton takes place to
up to 30%.
• In many applications PET is first pre-shaped in
amorphous state and then given a uniaxial (fibers or
tapes) or biaxial (film or containers) crystalline
orientation.
• During Injection Molding PET can yield amorphous
transparent objects (Cold mold) or crystalline opaques104
objects (hot mold)
PBT Chemical Structure and Applications
• The longer, more flexible (CH2)4 groups allow for more
rapid crystallization than PET.
• PBT is not as conveniently oriented as PET and is
normally injection molded.
• PBT has a sharp melting transition with a rather low melt
viscosity.
• PBT has rapid crystallization and high degree of
crystallization causing warpage concerns
105
Thermoplastic Aromatic Copolyesters
• Polyarylesters
– Repeat units feature only aromatic-type groups (phenyl or aryl
groups) between ester linkages.
– Called wholly aromatic polyesters
– Based on a combination of suitable chemicals
•
•
•
•
p-hydroxybenzoic acid
terephthalic acid
isophthalic acid,
bisphenol-A
– Properties correspond to a very stiff and regular chain with high
crystallinity and high temperature stability
– Applications include bearings, high temperature sensors, aerospace
applications
– Processed in injection molding and compression molding 106
Applications for Polyesters (PET)
• Blow molded bottles
– 100% of 2-liter beverage containers and liquid products
• Fiber applications
– 25% of market in tire cords, rope, thread, cord, belts, and filter
cloths.
– Monofilaments- brushes, sports equipment, clothing, carpet,
bristles
– Tape form- uniaxially oriented tape form for strapping
• Film and sheets
– photographic and x-ray films; biaxial sheet for food packages
• Molded applications- Reinforced PET [Rynite, Valox, Impet]
– luggage racks, grille-opening panels, functional housings such as
windshield wiper motors, blade supports, and end bells
107
– sensors, lamp sockets, relays, switches, ballasts, terminal blocks
Applications for Polyesters (PBT and LCP)
• PBT - 30 M lbs in 1988
• Molded applications (PBT) [Valox, Xenoy, Vandar, Pocan]
– distributers, door panels, fenders, bumper fascias
– automotive cables, connectors, terminal blocks, fuse holders and
motor parts, distributor caps, door and window hardware
• Extruded applications
– extrusion-coat wire
– extruded forms and sheet produced with some difficulty
• Electronic Devices (LCP) [26 M lbs] [Terylene, Dacron, Kodel]
– fuses, oxygen and transmission sensors
– chemical process equipment and sensors
– coil
108
Mechanical Properties of Polyesters
Mechanical Properties of polyester
PET
1.29-1.40
Density, g/cc
Crystallinity
PBT
1.30 - 1.38
LCP Polyester
1.35 - 1.40
10% - 30%
60%
>80%
7,000 – 10,500
8,200
16,000 – 27,000
400K - 600K
280K – 435K
1,400K - 2,800K
30% - 300%
50%-300%
1.3%-4.5%
0.25 - 0.70
0.7 - 1.0
2.4 - 10
65
60-95
25-30
70F -100F
122F - 185F
356F -671F
Molecular Weight
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
ft-lb/in
CLTE
10-6 in/in/C
HDT
264 psi
109
Physical Properties of Polyester
Optical
Tmelt
Tg
H20
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
PET
Transparent to
Opaque
245C -265 C
PBT
Opaque
LCP Polyester
Opaque
220C – 267C
400 C - 421 C
0.1 - 0.2% (24h)
0.085% (24h)
0.45% (Max)
<0.1% (24h)
<0.1% (Max)
good
good
good
Poor
Poor
none
Attacked by
halogen
hydrocarbons
Poor
good
good
Poor
Poor
Poor
Poor
fair
$0.53
$1.48
$7.00 - $10.00
73C - 80C
110
Advantages/Disadvantages of Polyesters
• Advantages
– Tough and rigid
– Processed by thermoplastic operations
– Recycled into useful products as basis for resins in such
applications as sailboats, shower units, and floor tiles
– PET flakes from PET bottles are in great demand for fiberfill for
pillows and sleeping bags, carpet fiber, geo-textiles, and regrind for
injection and sheet molding
– PBT has low moisture absorption
• Disadvantages
–
–
–
–
Subject to attack by acids and bases
Low thermal resistance
Poor solvent resistance
Must be adequately dried in dehumidifier prior to processing111to
prevent hydrolytic degradation.
Thermoplastic Copolyesters
• Copolyester is applied to those polyesters whose synthesis
uses more than one glycol and/or more than one dibasic
acid.
• Copolyester chain is less regular than monopolyester chain
and as a result has less crystallinity
• PCTA copolyester (Poly cyclo-hexane-dimethanolterephthalate acid) [amorphous]
– Reaction includes cyclohexanedimethanol and terephthalic acid
with another acid substituted for a portion of the terephthalic acid
– Extruded as transparent film or sheets that are suitable for
packaging applications (frozen meats shrink bags, blister packages,
etc..)
• Glycol-modified PET (PETG) [amorphous]
– Blow-molded containers, thermoformed blister packages.
112
ABS Background
• ABS was invented during WWII as a replacement for rubber
– ABS is a terpolymer: acrylonitrile (chemical resistance), butadiene
(impact resistance), and styrene (rigidity and processing ease)
– Graft polymerization techniques are used to produce ABS
– Family of materials that vary from high gloss to low matte finish,
and from low to high impact resistance.
– Additives enable ABS grades that are flame retardant, transparent,
high heat-resistance, foamable, or UV-stabilized.
113
PEEK History
• Polyether-ether-ketone (PEEK) and Polyether ketone (PEK)
– PEEK invented by ICI in 1982. PEK introduced in 1987
• PEEK and PEK are aromatic polyketones
– Volume for polyketones is 500,000 lbs per year in 1990. Estimated
to reach 3 to 4 million by 2000.
– Cost is $30 per pound (as of October 1998)
• Product Names
–
–
–
–
–
ICI: Vivtrex
BASF: Ultrapak
Hoechst Celanese: Hostatec
DuPont: PEKK
Amoco: Kadel
114
Chemistry & Chemical Structure
• PEEK- Poly-ether-ether-ketone
O
O
O
C
n
• PEK- Poly-ether-ketone
O
O
C
n
115
Chemical Synthesis
• Synthesis of polyketones
– PEK: Formation of the carbonyl link by polyaroylation from low
cost starting materials. Requires solvents such as liquid HF.
Excessive solvents and catalyst cause the high material cost.
O
O
O
C
+ HCl + CO2 +H20
C Cl
O
HF, catalyst
– PEEK: Formation
of ether link using phenoxide
n anions to displace
activated halogen.
PEK
O
F
C
F + OH
OH
K2CO3, DPS
PEEK + CO2 +H20 +KF
116
PEEK and PEK Applications
• Aerospace: replacement of Al
– Fuel line brakes to replacement of primary structure
• Electrical
– wire coating for nuclear applications, oil wells, flammability-critical mass
transit.
– Semi-conductor wafer carriers which can show better rigidity, minimum
weight, and chemical resistance to fluoropolymers.
• Other applications
–
–
–
–
–
–
Chemical and hydrolysis resistant valves (replaced glass)
Internal combustion engines (replaced thermosets)
Cooker components (replaced enamel)
Automotive components (replaced metal)
High temperature and chemical resistant filters from fiber
Low friction bearings
117
Mechanical Properties of PEEK
Mechanical Properties
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
PEEK
1.30-1.32
LCP Polyester
1.35 - 1.40
Nylon 6,6
1.13-1.15
10,000 – 15,000
16,000 – 27,000
14,000
500K
1,400K - 2,800K
230K – 550K
30% - 150%
1.3%-4.5%
15%-80%
0.6 – 2.2
2.4 - 10
0.55 – 1.0
R120
R124
R120
40 - 47
25-30
80
320 F
356F -671F
180F
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT
264 psi
118
Physical Properties of PEEK
Physical Properties
PEEK
Opaque
Optical
LCP Polyester
Opaque
Nylon 6,6
Translucent to opaque
400 C
255C – 265C
0.1-0.14% (24h)
0.5% (Max)
0.1% (24h)
0.1% (Max)
1.0-2.8% (24h)
8.5% (Max)
Oxidation
Resistance
UV Resistance
good
Good
good
Poor
good
Poor
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
good
good
good
Poor
Dissolved by phenol &
formic acid
Resistant
good
fair
Poor
Cost $/lb
$30
$7 - $10
$1.30
Tmelt
334 C
Tg
177 C
H2 0
Absorption
119
Properties of Reinforced PEEK
Mechanical Properties Reinforced
PEEK
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
1.30-1.32
PEEK 30%
glass fibers
1.52
PEEK with 30%
carbon fibers
1.43
10,000 – 15,000
23,000 – 29,000
31,000
500K
1,300K – 1,600K
1,900K – 3,500K
30% - 150%
2%-3%
1% - 4%
1.6
2.1 – 2.7
1.5 – 2.1
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT 264 psi
R120
R120
40 - 47
12-22
15-22
320 F
550F -600F
550F -610F
120
Processing Properties of PEEK
Processing Properties
Tmelt
Recommended Temp
Range
(I:Injection, E:Extrusion)
Molding Pressure
Mold (linear) shrinkage
(in/in)
PEEK
LCP Polyester
Nylon 6,6
334 C
400 C - 420 C
255C – 265C
I: 660F – 750F
E: 660F – 725F
I: 540F – 770F
I: 500F – 620F
10 -20 kpsi
5 - 16 kpsi
1 -20 kpsi
0.011
0.001 – 0.008
0.007 – 0.018
121
Advantages and Disadvantages of Polyketones
• Advantages
–
–
–
–
–
–
–
Very high continuous use temperature (480F)
Outstanding chemical resistance
Outstanding wear resistance
Excellent hydrolysis resistance
Excellent mechanical properties
Very low flammability and smoke generation
Resistant to high levels of gamma radiation
• Disadvantages
– High material cost
– High processing temperatures
122
Polyphenylene Materials
•Several plastics have been developed with the benzene ring in
the backbone
»Polyphenylene
»Polyphenylene oxide
(amorphous)
O
O
O
»Poly(phenylene sulfide)
(crystalline)
S
S
S
Cl
»Polymonochloroparaxylene
Cl
CH2
CH2
123
PPO and PPS Materials
*Advantages of PPS
*Advantages of PPO
- Usage Temp at 450F
- Good fatigue and impact
strength
- Good radiation resistance
- Good radiation resistance
- Excellent dimensional stability - Excellent dimensional stability
- Low moisture absorption
- Low oxidation
- Good solvent and chemical resistance
- Excellent abrasion resistance
*Disadvantages of PPS
*Disadvantages of PPO
- High Cost
- High cost
- High process temperatures
-Poor resistance to certain
chemicals
- Poor resistance to chlorinated hydrocarbons
124
PPO and PPS Applications
*PPS Applications
- Computer components
- Range components
- Hair dryers
- Submersible pump enclosures
- Small appliance housings
*PPO Applications
- Video display terminals
- Pump impellers
- Small appliance housings
- Instrument panels
- Automotive parts
125
PPS and PPO Mechanical Properties
Mechanical Properties
Density, g/cc
Tensile Strength,
psi
Tensile Modulus,
psi
Tensile
Elongation, %
Impact Strength
PPS
1.30
PPO
1.04 – 1.10
Nylon 6,6
1.13-1.15
9,500
7,800
14,000
480K
360K
230K – 550K
1% - 2%
60% - 400%
15%-80%
< 0.5
4-6
0.55 – 1.0
R123
R115
R120
49
60
80
275 F
118F -210F
180 F
ft-lb/in
Hardness
CLTE
10-6 mm/mm/C
HDT 264 psi
126
PPS and PPO Physical Properties
Physical Properties
PPS
Opaque
Optical
PPO
Opaque
Nylon 6,6
Translucent to opaque
255 C – 265 C
Tmelt
290 C
250 C
Tg
88 C
110 – 140 C
> 0.02% (24h)
0.01% (24h)
1.0-2.8% (24h)
8.5% (Max)
good
good
good
fair
fair
Poor
Poor in
aromatics
good
Poor in
aromatics
good
Dissolved by phenol &
formic acid
Resistant
poor
good
Poor
$2
$1.80
$1.30
H2 0
Absorption
Oxidation
Resistance
UV Resistance
Solvent
Resistance
Alkaline
Resistance
Acid
Resistance
Cost $/lb
127
PPS and PPO Processing Properties
Processing Properties
Tmelt
Recommended Temp Range
(I:Injection, E:Extrusion)
Molding Pressure
Mold (linear) shrinkage (in/in)
PPS
PPO
Nylon 6,6
290 C
250 C
255C – 265C
I: 600F – 625F I: 400F – 600F
E: 420F – 500F
I: 500F – 620F
5 – 15 kpsi
12 - 20 kpsi
1 -20 kpsi
0.007
0.012 – 0.030
0.007 – 0.018
• PPS frequently has glass fibers loaded up to 40% by weight
»Tensile strength = 28 kpsi, tensile modulus = 2 Mpsi, HDT = 500F
•PPO is frequently blended with PS over a wide range of percentages.
128
(Noryl from G.E.)
Section
Review
– Polyesters is one of many heterochain thermoplastics, which has
atoms other than C in the chain.
– Polyesters includes unsaturated (thermosets), saturated and
aromatic thermoplastic polyesters.
– Condensation polymerization for Polyester
–
–
–
–
–
–
Thermoplastic polyesters have ester(-C-O) repeating link
O
Linear and aromatic polyesters
Most thermoplastic LCP appear to be aromatic copolyesters
Effects of reinforcements on polyester
Effects of moisture environment on nylon
If cooled rapidly from the melt to a Temp below Tg, PET solidifies
in amorphous form. If reheated PET acquires 30% crystallinity
– PET has rigid group of (CH2)2 ; PBT has more flexible (CH2)4
129
– Copolyester chain is less regular than monopolyester chain and as
Section Review
– PEEK and PEK are aromatic polyketones.
– Ketone groups have R - O - R functionality.
– Chemical structure of PEEK and PEK depicts benzene - oxygen benzene in backbone.
– PEEK and PEK are used primarily in applications requiring high
temperature use and chemical resistance.
O
– AP2C is a special version of PEEK with 68% continuous carbon
fiber.
– Polyphenylene materials are plastics with the benzene ring in the
backbone.
– PPO and PPS are characterized as heterochain thermoplastics,
which has atoms other than C in the chain.
– PPO and PPS are made via Condensation Polymerization.
130
– PPS frequently has glass fibers loaded up to 40% by weight.
Section Review
•
Major Topics
– Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB.
– PVC is the leading plastic in Europe and second to PE in the US.
– PVC is produced by addition polymerization from the vinyl chloride monomer in a headto-tail alignment.
– PVC is partially crystalline (syndiotactic) with structural irregularity increasing with the
reaction temperature.
– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas
X1
– Vinyls have (CH2CX2) repeating link
– PS is Amorphous and made from addition polymerization
– PC is amorphous and made from condensation polymerization
– Effects of reinforcements on PP and PS
131
Section Review
• Major Topics
– Isotactic, atactic, sydiotactic polypropylene definitions
– Differences between PP and PE
– Molecular Weight definition and forms (Weight Average, Mw, and
Number Average, MA )
– Polydispersity definition and meaning
– Relation between Molecular weight and Degree of Polymerization
(DP)
– Mechanical, physical, and processing properties of PP,
Polybutylene, and polymethylpentene
– PP is produced with linear chains
132
Section Review
• Key Terms and Concepts
–
–
–
–
–
–
–
–
Polyolefin
Molecular weight
Number average molecular weight, weight average MW
Polydispersity
Polymer shrinkage
Polymer blends
Tensile Modulus
Izod Impact Strength
133
Homework Questions #2
1. Define Polyvinyls, PS, PP, HDPE, chemical structure.
2. Compare the density PVC, PVB, PS, and PVDC which is higher/lower than PP.
3. Compare the density of HDPE, LDPE, UHMWPE, LLDPE to PP?
4. What is the tensile strength of PP with 0%, 30% glass fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of PVC, PS, PP, LDPE and HPDE to look like:
50
Tensile
Strength,
10
Kpsi
xHDPE
xLDPE
200
500
Tensile Modulus, Kpsi
134
Homework Questions #2
6. Four typical Physical Properties of PVC are Optical = _______, Resistance to
moisture= ______ , UV resistance= _____, solvent resistance=_______
7. The Advantages of PP are ________, ________, _______, and __________.
8. The Disadvantages of PP are ________, ________, _______, and __________.
9. Glass fiber affects PP by (strength) ________, (modulus)________,
(impact)_______, (density) __________, and (cost) ____________.
10. Two Blends PVC are ___________, and __________.
135
Homework Questions #2
11. Define Polypropylene chemical structure
12. Does commercial PP have Isotactic, atactic, sydiotactic form.
13. If MW of PP is 200,000, what is the approx. DP?
14. Polydispersity represents the distribution of _______and _____
15. Density of PP is _____ which is higher/lower than HDPE.
16. PP mechanical properties are higher/lower than LDPE and HDPE
17. Plot tensile strength and tensile modulus of PP, LDPE and HPDE to look like the
following
50
Tensile
Modulus,
10
Kpsi
xHDPE
xLDPE
2
5
Tensile Strength, Kpsi
136
Homework Questions #2
18. Four typical Physical Properties of PP are Optical = _______, Resistance to
moisture= ______ , UV resisance= _____, solvent resistance=_______
19. The Advantages of PP are ________, ________, _______, and __________.
20. The Disadvantages of PP are ________, ________, _______, and __________.
21. Glass fiber affects PP by (strength) ________, (modulus)________,
(impact)_______, (density) __________, and (cost) ____________.
22. Five polyolefins are ________, ________, _______, ______, and __________.
137
Homework Questions
1. Define PEEK, PPO and PPS chemical structures.
2. How are the properties of PEEK and PPS alike?
3. Density of PEEK is _____, PPS is _____ , and PPO is
_____ , which is higher/lower than PBT and nylon?
4. What is the tensile strength of PEEK with 0%, 30% glass
fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of PEEK, PPO,
PPS, PET, PBT, Nylon 6, PP, LDPE and HPDE to look like
the following
50
xHDPE
Tensile
Modulus,
10
Kpsi
xLDPE
2
5
Tensile Strength, Kpsi
138
Homework Questions
6. Four typical Physical Properties of PEEK are Optical =
_______, Resistance to moisture= ______ , UV resistance=
_____, acid resistance=_______
7. The Advantages of PEEK are ________, ________,
_______, and __________.
8. The Disadvantages of PEEK are ________, ________,
_______, and __________.
9. How are the properties of PPO and PPS alike? How are they
different?
10. What are 3 advantages that Nylon has over PPO and
PPS?_________________________________
________________________________________________
139
_.
Homework Questions
1. Define PBT and PET chemical structure.
2. Why was Carothers not successful in developing polyesters?
3. Density of PET is _____ which is higher/lower than PBT
and nylon?.
4. What is the tensile strength of PET with 0%, 30% glass
fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of PET, PBT,
Nylon 6, PP, LDPE and HPDE to look like the following
50
Tensile
Modulus,
10
Kpsi
xHDPE
xLDPE
2
5
Tensile Strength, Kpsi
140
Homework Questions
6. Four typical Physical Properties of Polyester are Optical =
_______, Resistance to moisture= ______ , UV resistance=
_____, acid resistance=_______
7. The Advantages of Polyester are ________, ________,
_______, and __________.
8. The Disadvantages of Polyester are ________, ________,
_______, and __________.
9. Glass fiber affects Polyester by (strength) ________,
(modulus)________, (elongation)_______, (density)
__________, and (cost) ____________.
10. What affect does the copolymer have on the crystallinity of
polyesters and
141
why?_________________________________
Homework Questions
1. Define Nylon 6,6 and Nylon 6 and Nylon 6,12 chemical
structure
2. If MW of PA is 50,000, what is the approx. DP?
3. Density of PA is _____ which is higher/lower than PP.
4. What is the tensile strength of nylon 6,6 with 0%, 30% glass
fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of Nylon 6, PP,
LDPE and HPDE to look like the following
50
Tensile
Modulus,
10
Kpsi
xHDPE
xLDPE
2
5
Tensile Strength, Kpsi
142
Homework Questions
6. Four typical Physical Properties of PA are Optical = _______,
Resistance to moisture= ______ , UV resisance= _____,
solvent resistance=_______
7. The Advantages of PA are ________, ________, _______,
and __________.
8. The Disadvantages of PP are ________, ________,
_______, and __________.
9. Glass fiber affects PA by (strength) ________,
(modulus)________, (impact)_______, (density)
__________, and (cost) ____________.
10. Two Aromatic PA are ___________, and __________.
143