Dr. Andrew Clark
Senior Lecturer in Synthetic Chemistry
Research areas
Natural product isolation and total synthesis.
Chemistry and biology of free radicals
Development of synthetic methodology using copper, iron
and ruthenium
Functional Genomics / Chemical Genetics / Interactomics
Use of plants in renewable plastics manufacture
Use of plants in renewable plastics manufacture
POLYMERS and COMPOSITES
Resins/Monomers
Normally made from organic chemicals which are petrochemical
in origin.
Plant oils e.g. rape oil, linseed oil, sunflower oil, soya oil
Strengtheners
Normally a fibre incorporated into the polymer to increase
mechanical strength.
Plant fibres e.g. hemp, flax, jute, miscanthus
Fillers
Cheap organic or inorganic materials used to bulk the polymers
and to alter physical properties
Plant protein / waste e.g. rape meal
ADVANTAGES OF PLANT PRODUCTS OVER
PETROCHEMICALS
Non-toxic,
Biodegradable,
Non-polluting in water courses,
Sustainable,
Recyclable?
Besides a competitive price, the chemical industry
also wants improved or new properties from end
products derived from vegetable oils
Vegetable Oils as Polymer Feedstocks
(monomers)
Euphorbia oil
Rapeseed oil
Plant fibres for composites
Jute
Hemp
: Specific tensile strengths of synthetic and natural fibres
COMMON MONOMER FEEDSTOCKS
POLYURETHANES
OH
hydroxylated
monomers
OH
Flexible and rigid foams
elastomers and extrusions,
coatings, adhesives
POLYESTERS
Flooring, autobody repair, boat hulls
O
Epoxidised
monomers
O
EPOXY RESINS
Protective coatings, adhesives
flooring, plasticizers, foams
10 6 tonnes per annum
POLYURETHANES
O
OH
hydroxylated
monomers
OH
hydroxylated
monomers
NCO
Isocyanate
monomers
NCO
catalyst
O
O
HN
Isocyanate
monomers
Renewable sources of monomers for polyurethane synthesis
OH
hydroxylated
monomers
OH
TYPE 1
CASTOR OIL
TYPE 2
CARDANOL
cashew nut shell liquid
OH
O
O
R
O COR
O
R
O
OH
C15H29
steps
N
N
C15H29
OH
OH
oleic
O
O
R
O
O
R
O
R
O
linoleic
linolenic
O
Vernolic
Rapeseed
O
O
R
O
O
R
O
R
O
Euphorbia
acid, H 2O
H2O2, W, H 3PO4
Room temperature
OH
OH
O
epoxide
acid, H 2O
OH OH
alcohol
HO
O
ring opening
epoxidation
RAPESEED
RAPESEED
RAPESEED
OH
HO
O
OH
RASOR
OH
OH
OH OH
O
epoxidation
EUPHORBIA
RAPESEED
OH
OH
OH OH
high-EURE
HO
OH
ring opening
EUPHORBIA
ring opening
O
EUPHORBIA
RAPESEED
HO
OH
low-EURE
INFRA RED OF RAPESEED AND HYDROXYLATED RAPESEED
O
epoxidation
RAPESEED
RAPESEED
O
HO
OH
ring opening
RAPESEED
HO
OH
RASOR
HO
OH
OH
HO
RAPESEED
+
HO
O
O
HO
OH
OH
HO
HO
OH
OH
O
O
RAPESEED
HO
OH
RAPESEED
HO
RAPESEED
O
OH
HO
OH
OH
O
OH
OH
OH
OH OH
O
epoxidation
EUPHORBIA
RAPESEED
OH
OH
OH OH
high-EURE
HO
OH
ring opening
EUPHORBIA
ring opening
O
EUPHORBIA
RAPESEED
HO
OH
low-EURE
100
Transmittance (%)
80
60
OH
40
C=O
Euphorbia low-OH
Euphorbia high-OH
20
0
4000
3500
3000
2500
2000
1500
1000
-1
Wavenumber (cm )
Infra Red of modified low hydroxylated and high hydroxylated euphorbia
POLYMERISATION
THREE CLASSES of RESIN
RAPESEED HYDROXYLATED RESIN (RASOR)
EUPHORBIA HIGH HYDROXYLATED RESIN (high-EURE)
EUPHORBIA LOW HYDROXYLATED RESIN (low-EURE)
DI-ISOCYANATES
MDI
TDI
COMPOSITES
HEMP (H)
MISCANTHUS
FLAX
JUTE (J)
COMPRESSION MOULDING
100
Transmittance (%)
80
60
OH and NH
NCO
40
C=O
Euphorbia-OH
Euphorbia 50min
Rapeseed 50min
20
0
4000
3500
3000
2500
2000
1500
1000
-1
Wavenumber (cm )
IR spectra of 50 min cured rapeseed and euphorbia oil
Differential scanning calorimetry (DSC) analysis:
200
180
RASOR
Heat of reaction (delta H-J/g)
160
140
120
100
80
60
40
20
0
0
10
20
30
40
50
60
70
80
90
Time (min)
Isothermal cure characteristics of MDI polymerised
o
rapeseed resin (50 C, 180 J/g)
THERMAL GRAVIMETRIC ANALYSIS OF MATERIALS
The loss in mass as a function of temperature
Rapeseed oil
Hydroxylated oil
MDI polymerised
Hemp-RASOR
composite
100
Mass loss (%)
80
60
40
RAPESEED
20
0
0
200
400
600
o
Temperature ( C)
800
THERMAL GRAVIMETRIC ANALYSIS OF MATERIALS
The loss in mass as a function of temperature
RAPESEED
EUPHORBIA
100
Rapeseed oil
Hydroxylated oil
MDI polymerised
Hemp-RASOR
composite
100
80
Mass loss (%)
Mass loss (%)
80
60
40
Euphorbia oil
Hydroxylated
Euphorbia resin
Hemp-EURE
composite
60
40
20
20
0
0
0
200
600
400
o
Temperature ( C)
800
0
200
400
600
o
Temperature ( C)
800
THERMAL GRAVIMETRIC ANALYSIS OF MATERIALS
EUPHORBIA
30
Neat EURE
Hemp-EURE
Mass loss (%)
25
20
15
10
5
0
0
200
400
600
800
o
Degradation temperature ( C)
1000
Untreated and alkali treated hemp-EURE and hemp-RASOR
composites
45
40
HEURE low-OH
HEURE high-OH
Alk HEURE high-OH
40
Untreated HRASOR
Alk HRASOR
30
Tensile strength (MPa)
Tensile strength (MPa)
35
30
25
20
15
20
10
10
5
0
0
0
1
2
3
Strain (%)
4
5
0.0
0.5
1.0
1.5
2.0
Strain (%)
2.5
3.0
3.5
Composite
type
Fibre
volume
(%)
Tensile
strength
(MPa)
Young’s
Modulus
(GPa)
Composite
density
(Kg/m3)
Impact
strength
(kJ/m2)
ILSS
(MPa)
HEURE-lowOH
21.05
22.91
(1.06)
2.31
649.55
18.81
(2.17)
3.12
HEURE-highOH
18.89
26.56
(1.85)
2.78
625.07
7.03
(1.13)
3.49
(0.45)
HRASOR
19.92
38.84
(2.21)
3.40
697.09
9.25
(1.21)
3.88
(0.45)
AHEURE-highOH
20.39
34.69
(3.76)
3.13
675.46
9.15
(1.64)
4.73
(0.76)
AHRASOR
19.20
23.82
(2.96)
2.35
633.16
10.47
(2.01)
3.81
(0.43)
JEURE-highOH
23.77
55.52
(2.60)
4.26
658.59
10.60
(2.27)
4.95
(0.43)
JRASOR
23.74
46.38
(3.37)
3.89
704.93
13.70
(1.95)
3.99
(0.82)
AJEURE-highOH
22.69
26.76
(2.23)
2.52
663.34
8.33
(0.88)
3.45
(0.45)
AJRASOR
22.70
26.84
(1.60)
2.61
655.23
13.34
(1.78)
3.55
(0.66)
60
Tensile strength (MPa)
50
40
30
20
10
0
1
JEURE
high-OH
2
AJEURE
high-OH
3
JRASOR
4
AJRASOR
22
20
16
2
Impact strength (kJ/m )
18
14
12
10
8
6
4
2
0
Unhemp
-EURE
low-OH
Unhemp
-EURE
high-OH
Alkhemp
-EURE
high-OH
Unhemp
RASOR
ALkhemp
-RASOR
SCANNING ELECTRON MICROSCOPY
RAPESEED PU
EUPHORBIA PU
RAPESEED-HEMP COMPOSITE
EUPHORBIA-HEMP COMPSITE
WEATHERABILITY
NO evidence of major decomposition after
6 months simulated Solar UV radiation
BIODEGRADABILITY
Samples buried in bags 6 x 6 cm (pore size 20 micron)
Bags recovered after three and six weeks
Weight loss and colonising flora analysis
Sample
Weight loss after 6 weeks [%]
Euphorbia polyurethane (EURE)
15.2
Rapeseed polyurethane/hemp composite
(hemp-RASOR)
52.2
Euphorbia polyurethane/hemp composite
(hemp-EURE)
50.3
Rapeseed polyurethane (EURE)
12.4
BIODEGRADABILITY
RASOR SEM
123 4 5 6 7 8 910111213
1= 3 weeks hemp-EURE
2= 3 weeks hemp-RASOR
3= 6 weeks hemp-EURE
4= 6 weeks hemp-RASOR
1 = ladder DNA, 2-5 = soil DNA,
6-9 = 3 wks, 10-13 = 6 wks
6, 10 = microflora DNA from EURE
7, 11 = microflora DNA from hemp-RASOR
8, 12 = microflora DNA fromhemp-EURE
9, 13 = microflora DNA from RASOR
1 2 3 4
Economics.
Cost of oil production per kilo
Euphorbia lagascae
£1.61
Rapeseed oil
£2.11
Castor oil
£1.21 * not including import costs
Cost of complete polyurethane production per kilo
Euphorbia lagascae
£1.54
Rapeseed oil
£1.88
Petrochemical
£2.50-£9.50
Energy required in monomer production
1.9kg of fossil fuel per kg of monomer
Equates to 3.1 kg of CO2 emissions per Kg of monomer
CONCLUSIONS AND RELEVANCE
A range of materials from rapeseed oil and euphorbia oil have been prepared and analysed.
Properties of materials produced differ depending upon the type of oil used.
Fibre composites of resins give superior properties to resins alone.
Biodegradability may be controllable
The increased range of materials available from this project will broaden the
portfolio of potential industrial applications of materials from renewables which
should lead to an increased value added market for fibres and oil crops in the UK
agricultural sector.
Euphorbia lagascae is a potential new crop for renewable materials production
Future work
In depth biodegradation studies. Can we control rate of degradation?
Use of other oilseed crops and fibre crops.
Use of fillers (rapemeal)
Portfolio of materials from renewables to showcase to industry
ACKNOWLEDGEMENTS
Chemistry Department, University of Warwick, Coventry, CV4 7AL
Dr. A. J. Clark,
Project leader, Chemistry, monomer production
Dr. L. Mwaikambo,
Polymer synthesis and characterisation
Prof. T. J. Kemp,
Weatherometry
Mrs. A. Mohd Rus,
Weatherometry
Advanced Technology Centre, Warwick Manufacturing Group, University of
Warwick, Coventry, CV4 7AL,
Dr. N. J. Tucker,
Project leader, Composites, mechanical testing
Biological Sciences, University of Warwick, Coventry, CV4 7AL,
Dr. M. Krsek,
Biodegradability
Prof. E. M. H. Wellington,
Biodegradability
ADAS (Euphorbia supplier)
Mr. D. Turley,
Malton, N
Dr. R. M. Weightman
Boxworth,
Formally of ADAS, High Mowthorpe, Duggleby,
Yorks, YO17 8BP.
ADAS Consultancy Ltd, Battlegate Road,
Cambs, CB3 8NN