摘要

The composites are mainly composed of two parts: polymer matrix and rigidreinforcement. Traditionally, the matrix resins depend heavily on petroleum resources which is rapidlydepleting and also cause many environmental problems. The Affordable Composites from RenewableResources (ACRES) program at the University of Delaware has developed a broad range of polymersfrom natural plant oils. These low cost, biodegradable, high performance resins open a big market on newbio-based materials which would have significant economic advantage and environmental impact.Triglycerides are the main component of natural plant and animal oils. Triglycerides are three-armed starscomposed of three fatty acids joined at a glycerol juncture. Most common fatty acids range in length from16 to 22 carbons long with unsaturation varying from 0-3 double bonds. Numerous synthetic routes havebeen developed to synthesize monomers which can copolymerize with other co monomers, such asstyrene and methyl methacrylate to form rigid thermoset resins with a wide range of physical properties.These polymers exhibit flexural strength in the range of 50-100 Mpa, flexural modulus 1.5-3.0 Gpa andglass transition temperature 70-160 °C. These resins are suitable for the general liquid molding process,and one specialty is the development of new sheet molding compounds (SMC) resins which havecomparable properties with commercial unsaturated polyester. It was demonstrated that these new SMCresins show thickening behavior with divalent metal oxides and good compatibility with commercial lowprofile additives. Lignin was successfully modified to enforce these polymer matrices, which cancontribute to the use of the waste product. Nanocomposites have attracted much interest in recent 10 yearssince the development of a nylon-6/clay nanocomposite by Toyota researchers. New bio-basednanocomposites were developed using these triglycerides-based polymers, carbon nanotube and organotreatedclays. The multi-walled nanotubes were prepared by the arc discharge method in Trinity College,Dublin, Ireland. Initial study showed that the nanotubes can disperse in these polymer matrices very welland significantly increase the mechanical properties. Organo-treated clays were also used to enforce thepolymer matrix. Both XRD and TEM confirmed the formation of nanocomposites. Flexural modulusincreased 30% at only 4 vol % clay content, but there is no significant effect on flexural strength and glasstransition temperature. This work is supported by NSF, DOE and EPA.