用DSC研究阻燃PET的结晶性和结晶动力学

<正> 聚对苯二甲酸乙二酯(PET)是一种熔点较高的结晶性聚合物,其结晶性和结晶动力学已得到了广泛的研究。我们最近合成的一种含磷聚合物(或齐聚物)聚苯基磷酸二苯砜酯(PSPPP),可作为PET纺丝较为理想的阻燃剂。当PET中添加5wt％的这种阻燃剂时,其极限氧指数可达到30。然而,有关这种阻燃剂的加入对PET结晶特性的影响方面的研究鲜见报道。本文用DSC方法研究了阻燃剂添加量的多少对PET结晶程度的影响,并且对纺制阻燃PET纤维的实用添加量5wt％的试样进行了结晶动力学研究。

STUDIES ON THE CRYSTALLIZABILITY AND CRYSTALLIZATION KINETICS OF FLAME-RETARDANT PET BY DSC

Both super-cooling(△Tsc) and super-heating (△Tsh) temperatures of polyethylene tereph-thalate (PET) containing 0,5,10 and 15 weight percent flame retardants have been determined by DSC curves. PET with 5 wt% flame retardant has the smallest △Tsc and △Tsh, which means that it has stronger crystallizability than the others. Avrami equation for the isothermal crystallization has been extended to the non-isothermal process of the constant heating rates so that the parameters characterizing crystallization kinetics, such as Avrami exponent n, the half life of crystallization t1/2 and the crystallization rate constant K, which are usually obtained from Avrami equation, can be calculated from the extended equation for non-isothermal crystallization. This method has been applied into the investigation of crystallization kinetics of PET and PET with 5 wt % of flame retardant. The results show that the value of t1/2 of PET with 5 wt% of flame retardant is smaller than that of pure PET, and that the value of n of the former is about 1 less than that of the latter.