裂解气相色谱质谱法研究增塑剂邻苯二甲酸二甲酯的热降解机理

Study on the Mechanism of Thermal Decomposition of Dimethyl Phthalate by Pyrolysis GC/MS

用裂解气相色谱-质谱联用方法研究了橡胶产品中使用的增塑剂邻苯二甲酸二甲酯(DMP)在不同温度条件下的热裂解行为.对不同温度条件下裂解产物的分析表明,在初始阶段DMP的裂解产物主要为二氧化碳、苯、甲苯和苯甲酸甲酯.随着温度的升高苯甲酸甲酯进一步裂解成为分子质量更小的自由基,并发生稠环化反应形成更稳定的菲、蒽、间-联三苯、三亚苯等芳香族多环化合物.根据分析实验提供的裂解产物信息和有机物热裂解化学反应的原理对DMP的热裂解反应机理作了探讨,表明在废旧合成橡胶热裂解回收过程中,增塑剂DMP的高温裂解会产生多环芳烃污染物.应选择合适裂解工艺和裂解温度,以减少对环境的污染.

Pyrolysis of Dimethyl phthalate （DMP） is conducted at different temperatures. The Pyrolysis products were analyzed by means of GC/MS. The results indicated that the main pyrolysis products of DMP were Carbon dioxide, Benzene, Toluene, Benzoic acid methyl ester. Then Benzoic acid methyl ester were Pyrolysised into smaller mass radicals. Polycyclic aromatic hydrocarbons such as Phenanthrene, Anthracene,m- Terphenyl,Triphenylene were found with the temperature increasing. Pyrolysis reaction mechanism of DBP degradation was discussed according to the Pyrolysis products. The propor temperature and techonology of pyrolysis should be applied to decrease the environment pollution.