尼龙1212/尼龙6共混体系的非等温结晶行为

用DSC研究了尼龙 12 12 ,尼龙 6及其共混体系的非等温结晶行为 .结果表明 ,加工历史对尼龙的结晶和熔融行为影响很大 .经双螺杆挤出机挤出的尼龙 12 12和尼龙 6 ,由于应力诱导分子链取向 ,其结晶温度都有不同程度的提高 ,且表现出多重熔融现象 .在共混体系中 ,尼龙 12 12分子在共混物的界面上异相成核结晶 ,提高了其结晶温度 ,但酸酐化SEBS的加入抑制了分子链的运动又使其结晶温度降低 .共混体系降低了尼龙12 12的熔融温度 ,并使得其高熔点的熔融峰逐渐消失 ;而尼龙 6的熔融行为基本上没有变化 .

NONISOTHERMAL CRYSTALLIZATION BEHAVIOR OF NYLON 1212/NYLON 6 BLENDS

Nonisothermal crystallization behavior of nylon 6,nylon 1212 and their blends using maleated SEBS as compatibilizers were studied by differential scanning calorimetry (DSC).The results showed that the processing history had a great influence on the crystallization and melt behavior of nylons.The extruded nylons showed improved crystallization temperature ( T c) and multiple melting phenomena due to the stress induced molecular orientation.In blends,the heterogeneous crystallization of nylon 1212 on the interface of nylon 1212 and nylon 6 occurred.Therefore,the T c of nylon 1212 was increased.With the addition of maleated SEBS,the formation of grafted copolymers between nylon 1212 and maleated SEBS restrained the movement of molecules and decreased the T c of nylon 1212 The melt temperature ( T m) of nylon 1212 was declined and the upper melting peak disappeared with increase of maleated SEBS in blends.However,the melt behavior of nylon 6 in blends was nearly unchanged.