用DSC评价PET的非等温结晶能力

Assessment of Nonisothermal Crystallizability of the PET by DSC

采用差示扫描量热法（ＤＳＣ）测定了４种含有特定催化剂体系及不同分子量的聚对苯二甲酸乙二醇酯（ＰＥＴ）试样的等速升温曲线及不同降温速率的降温曲线。实验结果表明：采用ＤＳＣ直接提供的热参数，如（ｔｃ－ｔｇ），ｔ＇ｃ，（ｔｍ－ｔ＇ｃ），（ｔ＇ｃ—ｔｃ）等均可评价ＰＥＴ的非等温结晶能力，并且具有较好的变化规律。对于结晶后期无明显二次结晶作用的试样，动力学结晶能力（Ｇｃ）也可以表征ＰＥＴ的非等温结晶能力．

y means of DSC,the constant heating rate curves and different cooling rate curves were determined for the four PET resins which contain different catalysts and have different molecular weights.The results show the thermal parameters,suhc as,(tc-tg),tc,(tm-tc),(tc-tc) etc.that obtained from DSC curves directly,can be used to assess the nonisothermal crystallizability of the PET with a good changing rule,the kinetic crystallizability(Gc) also can be used to characterize nonisothermal crystallizability of PET,if the secondary crystallization does not occur evidently in the process of crystallization.