(790b) Hyperbranching in Polytriglyceride-Based Thermoplastic Elastomers — Relationships Between Chain Architecture, Processing, and Properties

This contribution gives an overview of our recent work with the application of Atom Transfer Radical Polymerization to produce hyper-branched thermoplastic elastomers from triglycerides. ATRP uses the free radical propagation mechanism to produce homopolymers, statistical copolymers, and block copolymers with tailored architectures. This is made possible — as with other controlled radical polymerization chemistries — by the limitation of the free radical concentration to the picomolar range. We have tailored ATRP such that we are able to copolymerize multifunctional acrylated epoxidized triglycerides (from various vegetable oils) into either statistical or block architectures with styrene as the hard segment to form economical thermoplastic elastomers up to 750 kDa in molar mass. In this talk we will explain the distinct features of ATRP kinetics that allow the production of high polymers without gelation, and present melt state/solution rheology data, electron micrographs, and small-angle x-ray scattering data, that show how the properties of the elastomers are influenced by their chain architecture.