新型聚酯PMT等温结晶动力学研究

Study on isothermal crystallization kinetics of a new polyester——PMT

聚对苯二甲酸甲二酯 (PMT)是一种新型芳香族聚酯 ,本文以DSC差示扫描量热计对PMT的等温结晶动力学进行了研究 ,用Avrami方程对实验数据进行了分析 ,结果发现 :PMT的Avrami指数n在 2 4～ 2 6之间 ,为非整数且接近于 3,说明PMT结晶时倾向于异相成核 ;在实验温度范围内 ,随着等温结晶温度Tc的升高 ,PMT的结晶速率常数K减小 ,半结晶时间t1/ 2 增加。PMT的熔点与聚对苯二甲酸乙二酯 (PET)接近 ,但高于聚对苯二甲酸丙二酯 (PTT)和聚对苯二甲酸丁二酯 (PBT) 。

The isothermal crystallization kinetics of a new polyester——poly(methylene terephthalate) (PMT) was studied by using differential scanning calorimeter (DSC). The data was analyzed by the avrami equation and the result showed that the avrami constant n of PMT is located between 2.4 and 2.6. In the experimental temperature range, the crystallization rate constant K was decreased and crystallization half-time t_(1/2) was increased with the enhancement of crystallization temperature. The melting point of PMT is similar to that of poly(ethylene terephthalate) (PET) and is much higher than that of Poly(trimethylene terephthalate) (PTT) and Poly(butylene terephthalate) (PBT), which is in accordance with the structure study.