摘要:
The brittleness of a thermoplastic material containing a polylactic acid may be reduced by melting and mixing the thermoplastic material and a graft copolymer to link the graft copolymer to thermoplastic polymer to form a new thermoplastic material with reduced brittleness. The graft copolymer comprises an elastomeric backbone and a side chain grafted to the backbone. The side chain comprises a enantiomer of lactic acid opposite to the enantiomer in the thermoplastic material. A composition comprises a thermoplastic polymer and the graft copolymer, where the graft copolymer is linked to the thermoplastic polymer by the enantiomers. A method of forming the composition may comprise melting precursors for the thermoplastic polymer and the graft copolymer, and mixing the precursors to allow the lactic acids to link the graft copolymer to the thermoplastic polymer.
摘要:
A composition is provided, which comprises chains comprising a first graft copolymer of a first elastomer and a poly(L-lactic acid), and chains comprising a second graft copolymer of a second elastomer and a poly(D-lactic acid). At least some of the poly(L-lactic acid) and poly(D-lactic acid) crosslink the chains. Poly(L-lactic acid) and poly(D-lactic acid) may form stereocomplexes that crosslink the chains. The chains may be crosslinked by crystalline structures formed from at least some of the poly(L-lactic acid) and poly(D-lactic acid) in discrete regions. The crosslinked chains may form a matrix. In a method of forming the composition, the first and second graft copolymers are mixed, such as by melt blending or solution casting, to form the composition. The graft copolymers may be formed by a “grafting-though” or “grafting-from” process. The composition may be useful under a relatively wide range of temperatures.