增韧尼龙6的结晶,热行为和加工性能

对聚烯烃弹性体接枝物(E-g-MA)和尼龙6的共混物的结晶、热行为和加工性能等方面进行了研究。 对不同比例的Ny6/E、Ny6/E-g-MA二元共混物进行了熔融指数的测定,Ny6/E的MI的变化随弹性体含量增加而下降,而相同比例的Ny6/E-g-MA的MI值明显低于前者。 对纯Ny6和相同比例的Ny6/E、Ny6/E-g-MA共混物进行了等温结晶速度的测定。 共混物的DSC、WAXD测定结果表明:E-g-MA的加入不会影响Ny6的热行为、晶胞参数和γ晶型的形成,也不会产生新的晶型。增韧尼龙6比纯尼龙6更有利于加工成型。

CRYSTALLIZATION THERMAL BEHAVIOR AND PROCESSING PROPERTY OF TOUGHENED NYLON 6

The crystallization, thermal behavior and processing property of the blends of polyole-fin elastomer grafter (E-g-MA) and nylon 6 were investigated.The melting indices (MI) was determined for Ny6/E and Ny6/E-g-MA binary blends in different proportion. While the MI value of Ny6/E decreases with increasing elastomer contens, the MI value of Ny6/E-g-MA in same proportion is evidently lower than the Ny6/ E. It is the fact that the formation of E-g-Ny6 graft copolymer increases the chain length and plays a role similar to cross-linking, thus leading to further decreases of the MI.The isothermal crystalline growth velocity is determined ior the pure nylon 6 and the Ny6/E and Ny6/E-g-MA blends in same proportion. Such experiment results show that the added E-g-MA plays the role of nucleating agent, reduces t1/2, enhances viscosity,and changes the Avrami index. The addition of the elastomer obviously alters the crystallization mechanism and growth mode ol nylon, but the variation of the elastomer contents does not influence the crystallization mechanism and growth mode of the binary blends.The DSC and WAXD determination of the blends further shows that the addition of the E-g-MA has no effect on the thermal behavior, the unit cell parameter and the formation of the y-crystal form.