聚十二烷二元酸丁二酯及其共聚酯的结晶行为研究

聚十二烷二元酸丁二酯是长碳链脂肪族聚酯中的一种新的聚合物材料．近年来，随着对环境问题的日益重视，利用脂肪族聚酯容易水解的特性，开发生物降解脂肪族聚酯材料的研究得到广泛开展．目前脂肪族二元酸酯的研究大多是围绕聚丁二酸酯、聚乙二酸酯及其共聚酯这一类降解速度较快的材料进行的．虽然这些聚酯已有部分商品化，但远远不能满足对特定降解速率材料的需求．长碳链脂肪族聚酯由于其具有类似PE的结构特征，又兼具聚酯的结构特征，有望在可降解包装材料、书籍装订、服装用热熔胶等方面获得广泛的应用．

CRYSTALLIZATION BEHAVIOR OF POLY(BUTYLENE DODECANEDIOATE) AND COPOLYESTER

The nonisothermal crystallization of poly(butylene dodecanedioate) was studied by differential scanning calorimetry,crystals of polyesters were observed through polarized optical microscope,and an Avrami method was used to analyze the kinetics of nonisothermal crystallization.The results showed that the crystallization temperature decreased slowly with an increase in the cooling rate.Furthermore,secondary nucleation was observed in the process of PBDD nonisothermal crystallization,and the Avrami exponential values n of PBDD indicated that the mechanism of crystallization was a tridimensional growth with heterogeneous and homogeneous nucleation.Meanwhile,the Avrami values n of P(BDD-co-BT)-20 is 1,which indicated that their mechanism of crystallization was a one-dimensional growth with heterogencous nucleation.Crystallization activation energies implied that it is easier to crystallize for copolyester.From the observed results of spherulites,it can be concluded that the size of spherulites decreases with increasing the content of terephthalic acid.