共聚型磷系阻燃聚酯聚合反应动力学及其性能

Kinetics and properties of phosphorus flame retardant copolymerized polyester

为探究共聚型磷系阻燃聚酯的反应规律及其影响因素,以2-羧乙基苯基次磷酸(CEPPA)为阻燃剂制备不同磷含量的阻燃共聚酯,建立了聚酯反应动力学模型并分析其影响因素。借助红外光谱仪、差示扫描量热仪、热失重测试仪、极限氧指数仪、锥形量热仪对聚酯的结构及性能进行测试与分析。结果表明:随着CEPPA质量分数的增加,缩聚反应活化能逐渐增大,最高增加至106.83kJ/mol;聚合物的玻璃化转变温度、熔点均呈下降趋势;阻燃剂中磷元素以共价键形式共聚到PET分子链中,抑制了分子链的结晶;当磷含量为1%时,阻燃共聚酯的极限氧指数达到31%,引燃时间明显延长,最大热释放速率降低了24%,阻燃效果显著。

In order to investigate the reaction law and influencing factors of copolymerized phosphorus-based flame retardant polyesters(PET),flame retardant co-PETs was prepared by using 2-carboxyethyl phenyl phosphinic acid (CEPPA) as a co-monomer flame retardant.The kinetic model of the polycondensation reaction of PET and flame retardant co-PETs were established,and the trend and reasons of the kinetic model were analyzed.The structure and properties of polymer were characterized by infrared spectroscopy,differential scanning calorimetry,thermogravimetry,limiting oxygen index and cone calorimetry.The results show that with the increase of the mass fraction of CEPPA,the actiration energy of reaction increases to 106.83 kJ/mol.The glass transition temperature and melting point decreases with the increase of the flame retardant because the group structure of CEPPA is polymerized into the macromolecular chain,which inhibits the crystallization of the PET.PET with the phosphorus content of 1% can achieve the optimal flame retardancy,limit oxygen index can be up to 31%,the ignition time is prolonged obviously,and the peak heat release rate decreases by 24%.