Polymeric Materials
Sunan Tiptipakorn, D.Eng.
Department of Chemistry,
Faculty of Liberal Arts and Science,
Kasetsart University, Kamphaen Saen Campus,
Nakorn Phathom, 73140 Thailand.
Introduction
Material Science
Relationship
Structure
Processing
Properties
Performance
Materials
Metals
Polymers
- organic polymers
- inorganic polymers
Composites
Ceramics
Semiconductors
Polymers
Thermoplastics
- can be recycled
Example:- PE, PP, PVC
Ref.: http://cltad.arts.ac.uk
Thermosetting
-can not be recycled
Ref.:http://www.resinsystems.com/products/highvoltageinsulators.html
Example:- polyurethane, epoxy
- no melting temp.
Ref.: http://www.emeraldinsight.com
Organic Polymers
Main Organic Polymers
6 types of well known thermoplastics
Extruder
http://commons.wikimedia.org/wiki/File:Extruder_section.jpg
http://www.synaflex.com/Products/ExtrudedRubberProducts
Polyethylene (PE)
Ethylene monomer
or
(Ethene)
polyethylene
(polyethene)
or
Ref.:http://www.yurak.com
PE granules: (1)Natural form,
(2) and (3) are colored with dyes
HDPE
(High Density Polyethylene)
Ref.: www.thaigoodview.com
high crystallinity (Linear PE)
Ref.:www.hdpe-containers.com/pipette-droppers.htm
LDPE
(Low Density Polyethylene)
Low crystalinity (Branched PE)
Ref.: http://www.waterwiseliners.co.za/Pondimages/ldpe%20pond.JPG
Branched Chains and Linear Chains
Ref.:http://www.makingthemodernworld.org.uk/learning_modules/chemistry/03.TU.02/?section=7
Free Radical Polymerization
High Temp.
High Pressure
Examples:LDPE
PVC
PS
Ref.: http://pslc.ws/mactest/radical.htm
Coordination Polymerization
Low Temperature
Low Pressure
Ziegler and Natta Catalyst
TiCl4 + Aluminium co-catalyst
Examples:
HDPE, PP
Ref.: http://chem.chem.rochester.edu/~chem421/zn.htm
Polypropylene (PP)
Ref.: www.vcharkarn.com/varticle/38233/2
Ref.:http://www.chemicals-technology.com/projects/hmcpolymers-thailand/
Three Types of Polypropylene
Ref.:http://www.steinwall.com/ART-polypropylene.html
Polystyrene (PS)
Types of Polystyrenes
Polyvinyl chloride
Polymerization: free radical chain polymerization
Morphology:
highly amorphous, ~11% crystallinity
Glass transition
~84 oC
temperature:
Ref.:http://www.vcharkarn.com/varticle/38233/2
Polyethylene terephthalate (PET)
Ref.:http://www.vcharkarn.com/varticle/38233/2
Organic Polymers
Benefits
Low Cost / Affordability
Electrical Insulation
Abrasive Resistance
Easiness to Process
Light-weight
Drawbacks
- Low performance @ high Temp.
- Swelling
organic solvent
- Flexibility @ low range of Temp.
- Low flame resistance
- Not suitable for artificial organs
Inorganic Polymers
Methodology
1) Addition of Side Groups
Addition polymerization of vinyl monomer
H
H
C
H
Vinyl monomer
Examples
X = SiCH3; OSiCH3; C6H5PO
C
X
Steric effect
Free Radical Polymerization
Coordination Polymerization
1) Addition of Side Groups (cont.)
Vinyl monomer
Copolymer with
Styrene
Methyl Methacrylate
Acrylonitrile
2) Coordination polymerization
of organometallic reagent
with organic polymer (e- donor)
Example
M
M = inorganic
Coordination bonding
3) Synthesis via polymers with
inorganic substance in main chain
3.1 Non-metallic inorganic substances
(Si, P, S, O, N)
3.2 Transition metals
Examples
Poly(organosiloxane) or Silicone
Phosphazene polymer
Metallo-backbone polymer
Main
chain
Polyorganosiloxane (Silicone)
Most commonly used : poly(dimethylsiloxane)
CH3
H3C Si
(CH3)2SiCl2
H2 O
-HCl
hydrolysis
dimethyldichlorosilane
O
O
H3C Si
CH3
Si CH3
O
O Si
CH3
CH3
CH3
octamethylcyclotetrasiloxane
CH3
O Si
acid or base
CH3 n
poly(dimethylsiloxane)
(MW > 25,000)
O2 penetration: artificial organs
Phosphazene Polymer
Conductive Polymer
R
N P
R n
n> 15000
Raw Materials: PCl5 + NH4Cl
Ring-opening polymerization
Macromoleular substitution reaction
Direct condensation
Phosphazene Polymer (cont.)
R
N P
R n
n> 15000
R changes
Properties changes
Cl - Inorganic rubber
- Organic solvent swelling
- Reacted with water
OCH2CF3
- water resistant
Applications: Dyes, gasket, O-ring, and etc.
Natural
Inorganic Polymers
Natural Inorganic Polymers
Characteristics
Three dimensional structure
Rigid and Brittle
Silicate
Ref.:http://beachcomberonsaipan.blogspot.com
Asbestos
Ref.: http://www.treehugger.com/2009/06/14-week/
Silica glass
Ref.: http://minerals.caltech.edu/Silica_Polymorphs/index.html
Silicic acid
-4H2O
OHO Si
Na+
OH
OH
Condensation
Polysilicate
Tetrahedral structure
Ref.: http://commons.wikimedia.org/wiki/File:Silicic_acid.jpg
http://minerals.caltech.edu/Silica_Polymorphs/index.html
Most well known polysilicate : Silica (SiO2)
Crystalline:
Quatz
Tridymite
Cristobalite
Amorphous
Molecular Alignments of Tetrahedral Molecules
in Various Patterns of (SiO4)4-
Zeolite
(SiO4)4- and (AlO4)5Polysilicate
Tetrahedral
aliminate
Crystalline aluminosilicate
http://img.alibaba.com/photo/10872242/Zeolite_From_Indonesia.jpg
To Soften water; act as catalyst in petrochemical plants
Basic Zeolite Structure
Ref.: http://www.cheresources.com/zeolitezz.shtml
Legend: Circle = Oxygen, Square = Silicon, aluminium
Tetrahedral
Ref.:http://www.moutere.com/stories/storyReader$39
Ionomer
Main chain: Hydrocarbon or Fluorocarbon
Side chain: Carboxylic or sulfonic group
Na+
http://www.jsce.co.kr/polymer_lecture/ionomer.html
Ref.: http://www.jsce.co.kr/polymer_lecture/ionomer.html
Ref.: http://www.jsce.co.kr/polymer_lecture/ionomer.html
Applications of Ionomers
Golf ball
Primer Coating
http://www.wemixallup.com/car-center-f35/car-paint-detailing-research-t180.htm
http://www.honeypixel.com/clients/inglewood/index.php?page=news-item-1
Ceramics
Ceramics
Compounds of
Silicates
Oxides
Carbides
Nitrides
Aluminates
Ref.:http://www.ceramickitchenware.com/
Ref.:http://www.selectcon.com/
Strong covalent bond with network structure
High strength and modulus
High thermal Resistance
Brittle
Ref.:http://www.ttc.most.go.th/
Manufacturing Steps
Milling to micron scale
Sintering
@ High Temperature
and High Pressure
Ref.: http://www.thaiceramicsociety.com/pc_burn_oxygen.php
Ref.: http://sandblastingabrasives.com/
Sol-gel Process
1. Mixing metal with alcohol to form metal alkoxide
Ti + C2H5OH
Ti(OCH2CH3)(s) + 2H2
2. Dissolving metal alkoxide and mixing with water
Ti(OCH2CH3)(solution) + 4H2O
Ti + H2O
Ti(OH)4(s) +4C2H5OH
Complex of Titanium Oxide and hydroxide
3. Dehydrating Ti(OH)4 with acid or base
Three dimensional network…..Gel
4. Burning gel @ 200-500oC
Ceramic Composites
Ceramics + Additives
Increase Toughness
Cutting machine, Grinding wheel
Ceramic Fiber of SiC or carborundum
Polydimthyl silane
Ceramic Fiber
400oC
Sintering
@1200oC
to remove
H2 and C atom
Ceramics
Alumina: Circuit Board
SiC:
Abrasive resistant materials
Ref.:http://dea.brunel.ac.uk/cleaner/Electronics_Projects/Handbook_2.htm
http://www.gravescompany.com/cabmate.htm
Quartz: piezoelectric
Ref.: http://www.britannica.com/EBchecked/topic-art/636716/108321/Typical-components-of-a-quartz-watch
La-Ba-Cu:Superconducting Ceramic
Piezoelectricity is the ability of some materials to generate an electric
field or electrical potential in response to applied mechanical stress.
Ref.:http://wever.wordpress.com/2008/07/
Reinforcing Elements
Pure Resin
Glass Fiber
Cellulose Fiber
Carbon Fiber
Aramid Fiber or Kevlar
Carbon Fiber
Most commonly used Acrylic Fiber: Polyacrylonitrile
Step 1
300oC
http://www.psrc.usm.edu/macrog/carfsyn.htm
Step 2
http://www.psrc.usm.edu/macrog/carfsyn.htm
Step 3
http://www.psrc.usm.edu/macrog/carfsyn.htm
Step 4
http://www.psrc.usm.edu/macrog/carfsyn.htm
Thermoplastic Elastomer
Thermoplastic Elastomer
Copolymer Behaviors:
Melt when heating (Thermoplastics)
Elastic (Elastomer)
Example
Butadiene + High Impact Polystyrene
PS
Butadiene
PS
Ref.: http://pslc.ws/macrog/kidsmac/rubber.htm
SBS Rubber
http://pslc.ws/macrog/kidsmac/rubber.htm
Polystyrene = tough hard plastic Æ durability.
Polybutadiene = rubbery materialÆrubber-like properties.
References:
1. Schaffer J.P. et al., The Science and Design
of Engineering Materials, R.D. Irwin Inc.,
Chicago, 1995.
2. Allen S.M. and Thomas e.L., The structure
of materails, The MIT Series in Materials Science
and Engineering, John Wiley and Sons. Inc.,
New York, 1999.
3. Allcock H.R. and Lampe F.W.,
Contemperary Polymer Chemistry, 2nd Ed.,
Prentice Hall, New York, Jersey, 1990.
Thank you
for your kind
attention