运用差示扫描量热仪研究了不同特性粘数（0．55～0．70 dL／g）的 PET非等温冷结晶和熔融结晶过程。结果表明，随着特性粘数降低，PET 样品消除热历史后的冷结晶起始温度θo 和峰温θp 向低温区偏移，半结晶时间 t1／2延长，特性粘数在0．617 dL ／g 以下，易形成完善的大尺寸结晶；PET 熔融结晶温度呈上升趋势，熔融结晶 t1／2降低，结晶速率增加，当特性粘数大于0．657 dL ／g 时，t1／2和 Avrami 指数 n 明显增加，不利于拉膜时铸片的均匀性。%The non-isothermal crystallization kinetics in cooling and melting crystallization of polyethylene terephthalate (PET)with different instinct viscous (0.55 ~0.70 dL /g)were studied by differential scanning calo-rimeter.The results showed that with the instinct viscous decreased,the temperature corresponding to cooling crys-tallization exothermic onset θo and peak θp decreased,the half-crystallization time t1 /2 was increased.When IV less than 0.61 7 dL /g,it was easy to form big size crystallization during cooling crystallization.With the instinct viscous decreased,the melt crystallization temperature of PET increased,the half-crystallization time t1 /2 decreased and the crystallization rate enhanced.When IV more than 0.657 dL /g,t1 /2 and Avrami index n increased obviously,and it was bad for producing film.
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