含氟PET的非等温结晶动力学

通过分子设计,在聚对苯二甲酸乙二酯(PET)大分子主链上同时引入耐热性的芳杂酰亚胺环和含氟基团。以六氟二酐和氨基十一酸为原料,通过热环化反应合成酰亚胺二酸,再用制备的酰亚胺二酸单体按照不同配比和对苯二甲酸二甲酯、乙二醇按一定比例调节投料比进行酯化缩聚反应,合成一系列含氟PET。利用差示扫描量热(DSC)法研究了聚合物非等温结晶行为,发现纯PET的结晶能力最强,随着含氟量的增加,结晶能力减弱。采用Jeziorny法分析了纯PET和含氟PET的非等温结晶动力学,发现结晶速率常数随着含氟链段的加入而减小,表明含氟链段的加入降低了PET的结晶能力。

Nonisothermal Crystallization Kinetics of Fluorine-Congtaining Polyethylene Terephthalate

The heat-resistant aromatic imide ring and fluorine-containing group were introduced into the macromolecular main chain of polyethylene terephthalate via molecular design. Diimide diacid monomer (DIDA) was synthesized through thermal cyclization reaction using 6FDA and 11-aminoundecanoic acid as raw materials. Fluorine-containing polyethylene terephthalate were prepared through esterification polycondensation among the as-synthesized DIDA,dimethyl terephthalate (DMT) and ethylene glycol (EG). The non-isothermal crystallization behaviors of the polyesters were tested by differential scanning calorimetry (DSC), and the results show that pure PET has the highnest crystallization ability,which is decreased with the increasing fluoride content. Non-isothermal crystallization kinetics of the polyesters are analyzed by the Jeziorny method. The kinetics datas indicate that the crystallization rate constant decreases with the increasing fluoride chain segment,and the crystallization ability of PET is reduced with the incorporation of the fluoride segment.