聚对苯二甲酸丁二醇酯/聚(对苯二甲酸丁二醇酯-e-己内酯)二元结晶共混体系的相容性和结晶行为

聚对苯二甲酸丁二醇酯(PBT)/聚(对苯二甲酸丁二醇酯-e-己内酯)(PBT-PCl)是一个新制备的具有分子间排斥相互作用的A/AxB1?x型两元结晶共混体系. 根据两元平均场模型,报道对苯二甲酸丁二醇酯(BT)与"-己内酯(CL)结构单元的相互作用参数为0.305. DSC研究发现,此共混物呈现了与典型的共聚物/均聚物共混物不同的结晶特征. PBT-PCL影响PBT链的活动力和晶片堆积;同时PBT-PCL的结晶受到先期结晶的PBT晶粒的阻滞. 尽管拥有相同的BT单元,共混的两组分在组成变化范围内仍没有形

Miscibility and Crystallization in Binary Crystalline Blends of Poly(butylene terephthalate) with Poly(butylene terephthalate-e-caprolactone)

Poly(butylene terephthalate)/poly(butylene terephthalate-e-caprolactone) is a new A/AxB1-x binary crystalline blend with intra-molecular repulsion interaction. Using the mean-field binary interaction model, the value of interaction parameter between the butylene terephthalate and caprolactone structural unit was first reported to be 0.305. This blend exhibited different crystallization behavior from a typical homopolymer/copolymer blend, which was carefully investigated by di?erential scanning calorimetry. It was found that poly(butylene terephthalate-e-caprolactone) copolymers have a great effect on the pure poly(butylene terephthalate) chain mobility and poly(butylene terephthalate) crystalline lattice packing. In the meantime, the crystallization of butylene terephthalate segments in copolymers was restricted by the previously formed poly(butylene terephthalate) crystallites. The two constituents for blending can not form a co-crystal in the range of composition even if they have the same butylene terephthalate unit. It can be concluded that longer segments in a copolymer would be beneficial for the formation of a co-crystal in blends.