三种耐热剂对全氟聚醚橡胶材料耐热性能的影响

研究了碳纳米管(CNTs)、有机蒙脱土(OMMT)、Fe_2O_3对全氟聚醚(PFPE)橡胶力学性能、压缩永久变形、热稳定性及耐热空气老化性能的影响;采用热分解动力学模型分析了未添加耐热剂的PFPE橡胶的热降解机制。结果表明:CNTs、OMMT、Fe_2O_3均能提高PFPE橡胶基体的热稳定性,其中,CNTs/PFPE橡胶复合材料起始热失重温度及失重5%时的温度相比未添加耐热剂的PFPE橡胶分别提高了32.1℃和29.0℃;Fe_2O_3能明显稳定PFPE橡胶基体在200℃热空气条件下老化72h后的性能。在空气及N_2气氛下,随着升温速率的提高,未添加耐热剂的PFPE橡胶的热失重曲线均向高温方向移动。根据Kissinger方程,计算出PFPE橡胶基体在空气气氛下的热解活化能为135.06kJ/mol,在N_2气氛下的热解活化能为262.46kJ/mol。

Effect of three heat-resistant agents on thermal properties of perfluoropolyether rubber

The effect of carbon nanotubes (CNTs), organic montmorillonite (OMMT), and Fe2O3 on the mechanical properties, thermal stability and hot aging resistance of perfluoropolyether (PFPE) rubbers were investigated.The thermal pyrolysis behaviors of pure PFPE rubber were analyzed by thermal decomposes method.The results indicate that dramatic increases in thermal stability are observed through the joined CNTs, OMMT and Fe2O3.Compared to pure PFPE rubber, the initial decomposition temperature and the 5% mass loss temperature of CNTs/PFPE rubber composite are 32.1℃ and 29.0℃ higher, respectively.The properties of Fe2O3/PFPE rubber composite after ageing at 200℃×72 h are obviously stabilized.The thermogravimetry and differential thermogravimetry curves of pure PFPE rubber move toward to high temperatures with increasing heating rate in air and N2.According to the Kissinger basic formula, the so-called activation energy of pure PFPE rubber is calculated to be 135.06 kJ/mol and 262.46 kJ/mol in air and N2, respectively.