染色改性共聚酯的热性能研究

在聚对苯二甲酸乙二醇酯(PET)分子链上分别引入聚醚、间苯二甲酸乙二醇酯-5-磺酸钠(SIPE)、脂肪链酯类,得到染色改性共聚酯,考察了改性组分对改性共聚酯热性能及热稳定性的影响。结果表明:改性共聚酯的玻璃化转变温度(T_g)均低于常规PET,醚改性共聚酯结晶性能稍好于常规PET,加入SIPE、醚型/酯型单体制备的共聚酯(ECDP)结晶性能弱于常规PET,其中酯型ECDP结晶能力最弱;在空气氛围下,改性共聚酯的非等温降解可分为三个阶段,第一阶段的降解活化能(△E)均小于常规PET,第二、第三阶段的△E大于常规PET;醚改性共聚酯的等温降解过程接近二级反应,ECDP的等温降解过程为一级反应。

Study on thermal properties of dyeing modified copolyester

Polyethers, sodium ethylene glycol isophthalate-5-sulfonate(SIPE)and aliphatic chain esters were separately introduced into polyethylene terephthalate(PET) molecular chain to obtain dyeing modified copolyesters. The effects of modified components on the thermal property and thermal stability of the modified copolyester were investigated. The results showed that the glass transition temperature(T_g) of the modified copolyester was lower than that of conventional PET, and the crystallinity of ether-modified copolyester was slightly better than that of conventional PET, the crystallinity of copolyester(ECDP) prepared by adding SIPE and ether/ester monomer was lower than that of conventional PET and ester-type ECDP had the lowest crystallinity;the non-isothermal degradation of modified copolyesters can be divided into three stages in air, and the degradation activation energy(△E) of copolyesters was lower than that of conventional PET at the first stage of degradation while △E was higher than that of conventional PET at the second and third stages;and the isothermal degradation process of ether-modified copolyester approached the second-order reaction, and that of ECDP was the first-order reaction.