Rubber Toughening of Polyamides with Functionalized Block Copolymers: 1. Nylon-6

摘要

The toughening of nylon-6 using triblock copolymers of the type styrene-(ethylene-co-butylene) styrene (SEBS) and a maleic anhydride (MA) functionalized version (SEBS-g-MA) is examined and compared with a conventional maleated ethylene/propylene elastomer. The changes in rheology, adhesion, crystallinity, morphology and mechanical behaviour associated with the reaction of the anhydride with the nylon-6 are documented. Combinations of the SEBS and SEBS-g-MA elastomer blends with nylon-6 give higher levels of toughening than is achieved with the functionalized elastomer alone. The particles of pure SEBS were about Slim in diameter (too large for toughening nylon-6), whereas SEBS-g-MA alone yielded particles of about 0.05 micrometer (apparently too small for optimal toughening). Combinations of the two types of elastomers gave a continuously varying particle size between these extreme limits. This suggests that the two rubbers form essentially a single population of mixed rubber particles. The order of mixing did not significantly affect the mechanical properties of these ternary blends. The evidence for maximum and minimum rubber particle sizes that can be effective for toughening nylon-6 is discussed.