This contribution presents � for the first time � the controlled radical polymerization of a vegetable oil into thermoplastic rubber, and the incorporation thereof into triblock copolymers with polystyrene to form thermoplastic elastomers. Increased costs of petrochemically-derived monomeric feedstocks such as butadiene has made biopolymers not only more environmentally friendly but also economically competitive. Over the past two decades, the production of bio-based polymers from plant oils has successfully brought forth thermoset materials through traditional free radical polymerization routes to yield highly crosslinked polymers; crosslinking beyond the gel point is to be expected owing to the inherent multifunctional nature of triglyceride-based monomers. We have discovered, however, that under the appropriate conditions controlled radical polymerizations such as Atom Transfer Radical Polymerization can sufficiently limit the polymerization of triglyceride so that it terminates at a desired molecular weight and block composition. Here we present multiple synthetic methods for these bio-based elastomeric block copolymers comprised of poly(acrylated epoxidized soybean oil) (PAESO) and polystyrene (PS).  The properties of these materials range from toughed glassy to tacky rubbers to resilient elastomers at room temperature but are amenable to common processing techniques at elevated temperatures, making them suitable for a wide range of applications. Finally, we investigate the viability of these materials in the specific application of bitumen modification, commercially representing a vast fraction of the thermoplastic elastomers market. Our findings have concluded thus far PS/PAESO-based block copolymers can match and even exceed the performance of petroleum-based polymers such as those of the Kraton(R) family.

Thermoplastic elastomeric block copolymers via controlled radical polymerization of soybean oil

244th National Meeting (2012)

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