Effect of Polyamide Functionality on the Morphology and Toughness of Blends witha Functionalized Block Copolymer

摘要

Previous work has shown that blends of a maleic anhydride functionalized triblockcopolymer (with an ethylene/butene mid-block and styrene end-blocks, or SEBS-g-MA) with nylon-6,6 gives super-tough materials with complex-shaped rubber particles that are just below the upper critical particle size for toughening. Similar blends of SEBS-G-MA with nylon-6 are not toughened because the rubber particles are evidently too small, i.e. below a proposed lower critical size for toughening. It was further proposed that this difference in morphology stems from the difunctional (nylon-6,6) versus monofunctional (nylon-6) character of these polyamides for reaction with anhydrides. This proposal is supported here by the observation that blends of SEBS-G-MA with nylon-12,12 give large complex rubber particles like those in nylon-6,6 while nylon-11 and nylon-12 give smaller particles like nylon-6. Further support of this notion is provided by blending nylon-6 with other polyamides in an attempt to produce a chemically modified matrix.