Sustainable Epoxy Materials From Vegetable Oils

Transcription

1 Sustainable Epoxy Materials From Vegetable ils Matthew Ravalli Ph.D. Graduate Student Department of Chemistry Rensselaer Polytechnic Institute, Troy, NY, USA Drs. James V. Crivello & Chang Y. Ryu Theodore Yang NSF DMR (Polymer Program) 2013 Rensselaer Nanotechnology Center Research Symposium Wednesday, November 6, 2013

2 verview Develop new, reactive monomers and polymers from sustainable, bio-renewable sources and understand their structureproperty relationships, considering: Substrates should be readily available in substantial quantities Minimum chemical modification should be needed Avoid use of any solvents Minimize reaction byproducts Use energy efficient polymerization schemes e.g. 1,3-propandiol By DuPont e.g. Polylactic acid NatureWorks e.g. epoxy tree? Dream

3 Approach Vegetable oils : Ester-based Monomer Source with Unsaturated Bonds (Triglycerides with unsaturated fat) Linseed oil Green Epoxy Coating & Composite Matrix

4 Epoxy Resins for thermoset composite matrix Conventional Two part Epoxy Epoxy monomers + Amine curing agent ( hardware store epoxy) Slow curing ur one part approach Epoxy monomers & photo-cationic catalyst PTENTIALLY Fast curing ( INK ) Epoxidized Soybean il ~ 1 % Z. J. Thompson and F. S. Bates et al. Macromolecules (2009) 42, Cross-linked Network Polymers (Thermoset)

5 Structures of Vegetable ils 5 = 4 = 6 = 4 = 4 = 3 = 7 = Soybean oil Price: $0.54/lb (2012) 6 =

6 Phase Transfer Epoxidation of Vegetable ils H2 L EL J. V. Crivello and R. Narayan Chem. Mater. 4(3), , 1992 C. Venturello and R. J. rg. Chem. 53(7), , 1988

7 Photo-Cationic Initiators NIUM Catalyst.. Ar 2 I + h ν ArI + - MtX n + Ar - MtX n Ar + MtX n - + ArI HMtX n HMtX n + M HM + MtX n - HM + MtX n - + nm H- ( M)nM + MtX n - Abs Quantum Yield For Photo-acid generation ~ 20% CH 2 -CH 2 -CH 2 n CH-CH 2 R R n CH-CH 2 -CH 2 - n CH-CH 2 R n R Ar 3 S + MtX n - or Ar 2 I + MtX n - + UV light R N R CH-CH 2 R n N-CH 2 CH 2 n C R (CH 2 ) 5 C n (CH 2 ) 4 - n J.V. Crivello JPS Part A (1999) 37, & Crivello and Lam Macromolecules (1977), 10, 1307.

8 Photo Polymerization of Epoxidized ils CH 2 C (CH 2 ) 7 CH CH CH 2 CH CH (CH 2 ) 4 CH 3 CH C (CH 2 ) 4 CH CH CH 2 CH CH CH 2 CH CH (CH 2 ) 4 CH 3 CH 2 C (CH 2 ) 7 CH CH (CH 2 ) 7 CH 3 Epoxidized Soybean il ES hν + I C 10 H 21 - SbF 6 CH 2 C (CH 2 ) 7 CH CH CH 2 CH CH (CH 2 ) 4 CH 3 CH C (CH 2 ) 4 CH CH CH 2 CH CH CH 2 CH CH (CH 2 ) 4 CH 3 CH 2 C (CH 2 ) 7 CH CH (CH 2 ) 7 CH 3 Crosslinked Network Polymer

9 Drawbacks to Epoxidized Vegetable ils as Monomers Low glass transition (Tg < RT) temperatures limit use to nonstructural applications Relatively slow photopolymerization kinetics EL or ES 2%wt IC-8 EL (Epoxidized Linseed il) ES (Epoxidized Soybean il) Temperature ( o C) Temperature ( o C) Time (seconds) 10 mins

10 Copolymerization with Terpene xides Photo-polymerization of α-pinene xide and Limonene xide are much more reactive than EVs. Pinene xide Limonine xide Co-polymerizations take increase the polymerization rate for EVs. EL (Epoxidized Linseed il) ES (Epoxidized Soybean il) 50% P 5% P

11 EL (Epoxidized Linseed il) Thermally-Cured EL: Rheology of EL 2% wt. IC % wt. 8%, Cu Napthenate (Thermal Catalyst) G ~ ω 0

12 Elastic Moduli of Crosslinked EVs il # Epoxy Groups / Monomer G, Pa (ω = 10 rad/s) G N EL x 10 8 M x =10.4 g/mol? Thermally-Cured EVs ES x 10 6 M x =310 g/mol VG x 10 5 M x =4500 g/mol M x

13 Rheology of EL M x ~ 10 g/mol (?) M x ~ 2000 g/mol

14 Conclusions Epoxidized vegetable oils (EVs) can be photo-crosslinked into a thermoset materials used for green composite matrix and coating. The elastic shear moduli (G ) of EVs ranges from 100 MPa ~ 1 MPa with G (G N ) ~ ω 0 G N (thermally cured) > G N (photo-cured) M x ~ 10 g/mol (?) M x ~ 2000 g/mol

15 Future Work Mechanical and thermal properties of the crosslinked epoxidized vegetable oils that provide different levels of crosslinking densities. Synthesis of EL of varied degrees of epoxidation M x of networked EVs from G N Tg at different levels of network density (i.e. M x ) Photo-curing Process: Interplay between Photopolymer kinetics and the arrest of network formation during crosslinking (due to the formation of network gels ) Search for co-monomers to improve reaction kinetics and mechanical properties.

16 Acknowledgements Scalable Green Chemistry Crivello/Ryu Research Group