含磷阻燃共聚酯的熔融增黏反应及其动力学

为分析高黏度含磷阻燃共聚酯熔融后增黏反应的影响因素,以2-羧乙基苯基次膦酸(CEPPA)为阻燃剂合成了系列含磷阻燃共聚酯切片,并进行熔融增黏反应,研究反应温度、反应时间及含磷阻燃剂质量分数对阻燃共聚酯增黏效果的影响。结果表明:阻燃单体可成功引入聚酯中;在一定温度范围内,含磷阻燃共聚酯的熔融缩聚增黏效果较好,当温度超过一定范围时降解反应加剧,增黏变得困难;阻燃剂添加量越高,共聚酯黏度增加越困难;缩聚反应动力学研究发现,含磷阻燃共聚酯的反应速率常数随温度的升高而增大,随阻燃剂添加量的增加而减小;反应活化能随阻燃剂添加量的增加而增大,最高达到114.73 k J/mol;基于正交试验分析熔融增黏反应的影响因素由大到小为反应时间、阻燃剂添加量、反应温度。

Melt polycondensation and kinetics of phosphorus containing flame retardant copolyesters

In order to study the influencing factors for melt polycondensation of high-viscosity phosphorus containing flame retardant copolyesters, flame retardant copolyesters with different phosphorus contents were synthesized by melt-polycondensation with 2-carboxyethyl (phenyl)phosphinic acid (CEPPA) as flame retardant. The melt polycondensation was conducted, and the effects of temperature, time and addition amount of phosphorus-containing flame retardant on intrinsic viscosity of copolyesters were investigated. The results show that the flame retardant is added into polyester successfully. The viscosity of copolyesters is increased significantly within a certain temperature range. When the temperature increases further, the degradation reaction intensified making the increase of viscosity more difficult. The more the addition of flame retardant, the more difficult it is to increase the viscosity. By establishing the reaction kinetics model, it was found that the reaction rate constant of flame retardant copolyesters increases with the increase of temperature, and decreases with the increase of flame retardant content.The activation energy increases with the increase of flame retardant content, the highest reaches 114.73 kJ/mol. The factors for melt polycondensation are analyzed based on the orthogonal experiment. The important order was found to be the reaction time, addition amount of flame retardant and reaction temperature.