热重分析法测定三元乙丙复合橡胶中组分

摘要

考察了三元乙丙复合橡胶溶剂抽出时间曲线、不同气氛和升温速率条件下组分的失重情况.结果表明高浓度矿物油条件下三元乙丙复合橡胶溶剂抽出时间应相应增加,氮气气氛中升温至650 ℃时碳酸钙可持续释放二氧化碳,而炭黑保持稳定.通过试验选择了热重法测定三元乙丙复合橡胶中各组分的测定程序:氮气氛中以30 ℃/min的升温速率从室温升至650 ℃,恒温25 min,降温至400 ℃后切换到空气或氧气气氛,然后以50℃/min的速率升温至800 ℃.%The solvent extract-time curve,thermal degradation characteristics of ethylene propylene diene ter-polymer(EPDM) compounded rubber were investigated. The results showed that more distillation time was needed to remove the solvent extract,when high content of rubber oil was added in EPDM. Calcium carbonate could release car-bon dioxide continuously when heated to 650 ℃ in the nitrogen atmosphere,while carbon black is thermally stable up to this temperature. The thermogravimetric analysis procedure of EPDM compounded rubber could be as follows: In the nitrogen atmosphere,raise the oven temperature to 650 ℃ at a rate of 30 ℃/min,and maintain the temperature for 25 minutes;lower the temperature to 400 ℃ and switch from the stream of nitrogen to a stream of air or oxygen, then raise the temperature to 800 ℃ at a rate of 50 ℃/min.