(750i) Biorenewable Tough Blends of Polylactide and Acrylated Epoxidized Soybean Oil Compatibilized By a Polylactide Star Polymer

applications in consumer products, disposable packaging, and textiles, among others. The

widespread application of this material is limited by its brittleness, as evidenced by low tensile

elongation at break, impact strength, and fracture toughness. A multifunctional vegetable oil,

acrylated epoxidized soybean oil (AESO), was investigated as a biodegradable, renewable

additive to improve the toughness of PLA. AESO was found to be a highly reactive oil,

providing a dispersed phase with tunable properties in which the acrylate groups underwent

crosslinking at the elevated temperatures required for processing the blends. Additionally, the

presence of hydroxyl groups on AESO provided two routes for compatibilization of PLA/AESO

blends: 1) reactive compatibilization through the transesterification of AESO and PLA and 2)

synthesis of a PLA star polymer with an AESO core. The morphological, thermal and

mechanical behavior of PLA/oil blends were investigated, in which the dispersed oil phase

consisted of AESO, soybean oil (SYBO), or a 50/50 mixture of AESO/SYBO. The oil additives

were found to toughen the PLA matrix, with significant enhancements in the elongation at break

and tensile toughness values, while maintaining the glass transition temperature of neat PLA. In

particular, the blend containing PLA, AESO, SYBO, and the PLA star polymer was found to

exhibit a uniform oil droplet size distribution with small average droplet size and interparticle

distance, resulting in the greatest enhancements of PLA tensile properties with no observable

plasticization.