Abstract: In order to study the melt polycondensation of flame retardant copolyesters containing phosphorus linked pendant groups, the flame retardant containing phosphorus linked pendant groups was successfully introduced into the polyester molecular chain by direct esterification method. The experiment for copolyesters containing phosphorus linked pendant groups (PET-D_x) was carried out for melt polycondensation, and the influence of different reaction factors (temperature, time and the amount of flame retardant additive) on the polycondensation reaction was analyzed. The results showed that the intrinsic viscosity of PET-D_x gradually increases with the increase of temperatures, while the intrinsic viscosity of copolyester decreases slightly later in the reaction. The steric resistance effect generated by the benzene ring structure in the flame retardant monomer has a certain inhibitory effect on melt polycondensation, and at 270 ℃, PET-D₃ with an addition of 3% flame retardant has the best viscosity enhancement effect, the reaction lasts for 2.5 h, and the intrinsic viscosity can reach 1.23 dL/g. Finally, the reaction kinetics of melt polycondensation was studied according to the change of intrinsic viscosity with reaction time. The results show that the reaction rate constants of the polycondensation reaction increase with the increase of temperature and the decrease of flame retardant content, while the activation energies increase with the increase of flame retardant content.

Key words: flame retardant containing phosphorus linked pendant groups, copolyesters, melt polycondensation, reaction kinetics

摘要： 为研究侧基含磷阻燃共聚酯的熔融增黏反应,将侧基含磷阻燃剂共聚到聚对苯二甲酸乙二醇酯(PET)分子链中,制得侧基含磷阻燃共聚酯PET-D_x。对PET-D_x进行熔融缩聚增黏反应,分析不同反应因素(温度、时间、阻燃单体添加量)对增黏反应的影响。结果表明:PET-D_x的特性黏度随温度升高而逐渐增加,而在反应后期略微降低;阻燃单体中苯环结构产生的位阻效应对熔融增黏具有一定的抑制作用,故在270 ℃下,阻燃剂添加量为3%的PET-D₃增黏效果最好,反应2.5 h,特性黏度可达1.23 dL/g。最后,根据特性黏度的时间演变特性对熔融缩聚增黏的反应动力学进行研究,反应速率常数随温度的升高、阻燃单体添加量的减少而增加,而反应活化能却随阻燃单体添加量的增加而增加。

关键词: 侧基含磷阻燃剂, 共聚酯, 熔融增黏反应, 反应动力学