초록 |
Poly(lactide) (PLA) is a renewable, degradable and compostable thermoplastic with mechanical properties similar to poly(styrene). Unfortunately, PLA is inherently brittle and possesses poor melt strength. In particular, the brittle nature of PLA limits its current utility to disposable packing. Melt blends of PLA and a rubbery material can rubber toughen the plastic. Current efforts explore using block and graft copolymers with a majority PLA block and minority rubbery block in which phase separate on the nanometer length scale to rubber can toughen PLA. Careful molecular design is needed to obtain the desired phase separation on nanometer length scale. To achieve these hierarchically structured materials for sustainability, toughness, degradability, and flexibility, various architectures via controlled polymerization/oligomerization, post-polymerization functionalization, and coupling chemistries need to be developed. |