叔丁基过氧化氢对聚丙烯腈环化反应的影响

Influence of tert-butyl hydroperoxide on cyclization of PAN

为加快聚丙烯腈(PAN)的预氧化速度,提高碳化收率,使用分解温度较高的叔丁基过氧化氢(TBHP)对PAN进行改性处理,得到TBHP/PAN改性膜,通过差示扫描量热仪、热重分析仪研究了TBHP对PAN环化反应的影响。结果表明,TBHP/PAN改性膜的环化反应起始温度为175℃左右,较未改性PAN膜降低了约90℃,最大放热峰值温度从277℃(未改性PAN膜)降低到260℃,放热峰宽化明显。环化反应动力学研究表明,TBHP/PAN改性膜的环化反应活化能为167.43kJ/mol,指前因子为1.34×10^(13)。预氧化处理后氮气气氛下TBHP/PAN改性膜700℃的热失重率为33.13%,较未改性PAN膜降低了6.12%。

To accelerate the stabilization process of polyacrylonitrile(PAN)and increase carbonization yield,tert-butyl hydroperoxide(TBHP)was used to modify PAN.The effects of TBHP on cyclization of PAN was studied using DSC and TG.The results showed that the initiate temperature of the cyclization for PAN was about 175℃,90℃lower than that of unmodified PAN.The exothermic peak temperature decreased from 277℃for unmodified PAN to 260℃for TBHP/PAN with broader peak width.Kinetic analysis results indicated that the activation energy of cyclic reaction for TBHP/PAN was 167.43 kJ/mol,and the pre-exponential factor was 1.34×10^(13).The weight loss in N_(2) of the stabilized TBHP/PAN was 33.13%,6.12%less than that of unmodified PAN.