阻燃剂聚丙烯酸五溴苄基酯的热分解动力学

Thermal Decomposition Kinetics of Flame Retardant Poly(pentabrombenzyl acrylate)

用热分析法研究了阻燃剂聚丙烯酸五溴苄基酯在空气和氮气气氛中的热分解动力学。该阻燃剂在空气气氛中为两步分解,在氮气气氛中为一步分解,利用Friedman法求出聚丙烯五溴苄基酯的第一步分解反应的活化能变化趋势,同时利用Satava-Sestak法研究了其热分解机理。结果表明,在0.10至0.90的转化率范围内,聚丙烯酸五溴苄基酯在空气气氛下的活化能为167.35kJ/mol,在氮气气氛下的活化能为171.94kJ/mol,热分解机理均为Avrami-Erofeev方程,随机成核和随后生长,反应级数分别为n=23和n=12。动力学方程分别为G(a)=[-ln(1-a)]23和G(a)=[-ln(1-a)]12。

The thermal decomposition kinetics of flame retardant poly （pentabrombenzyt acrylate） in air and nitrogen atmospheres were studied using thermal analysis technique. Poly （pentabrombenzyl acrylate） degraded in two steps in air and degraded in a single step in nitrogen. The activation energy of the first step of the decomposition process in two different atmospheres for the title compound were calculated through the Friedman method and the thermal decomposition mechanism of poly （pentabrombenzyl acrylate） was also studied with the Satava-Sestak method. The results showed that the activation energy of poly （pentabrombenzyl acrylate） in air and nitrogen was 167.35 kJ/mol and 171.94 kJ/mol respectively, for the decomposition rate from 0. 10 to 0. 90 . The thermal decomposition of poly （pentabrombenzyl acrylate） follows Avrami-Erofeev equation in both atmospheres, that means random nucleation, then 2 1 growth. The reaction orders are n =2/3 and n =1/2, and the kinetic equations can be expressed as G（a） = [-In（1 -a）]2/3 and G（a） = [-ln（1- a）]1/2 in air and nitrogen atmospheres, respectively.