涤纶与对乙酰氧基苯甲酸共聚酯的结构和性能的研究

本文对不同组成的涤纶与对乙酰氧基苯甲酸的无规共聚酯(PET-PHB)采用偏光显微镜、电子显微镜、X射线衍射及DSC等技术进行了研究。结果表明,当组成在～30(mol)％ PHB时开始出现热致性液晶,熔体变混浊,此时骤冷样品密度、平衡熔点、开始结晶的过冷程度及过热程度等与组成的关系都出现了突变。提出了液晶相中PHB-PHB链段可能存在以头尾相反方式形成的双链麻花棒按向列型方式排列。

STUDIES OF STRUCTURE AND PROPERTIES OF PET-PHB COPOLYESTERS

The random copolyesters (PET-PHB) of polyethylene terephthalate with different amounts of p-acetoxybenzoic acid have been investigated by several methods such as polarizing microscopy, scanning electron microscopy, X-ray diffraction, DSC, etc., The experimental results show that the nematic liquid crystal begins to appear at the composition of eopolyester 30(mol)% PHB, and at which the melt becomes turbid. Furthermore, an abrupt change can be found in the composition dependence of quenched-melt density, equilibrium melting point, the extant of super-cooling or the extent of superheating. And it can be related to the onset of liquid crystallinity.It has been proposed that the duple helices with reversed tail-to-head PHB-PHB segments exist in liquid crystal and arrange in a nematic pattern.