氟橡胶/改性乙丙橡胶并用胶的热稳定性

Thermal Stability of Fluoroelastomer/MEPDM Blends

采用热分析技术考察了氟橡胶及氟橡胶(FPM)/改性乙丙橡胶(MEPDM)并用胶在氮气中的热稳定性,通过微分法与积分法两种动力学方法计算出了FPM及FPM/MEPDM并用胶的热分解活化能E和指前因子A.结果表明,并用胶的热分解温度稍高于纯的氟橡胶,但热分解活化能略低于氟橡胶,FPM、FPM/MEPDM(5%)和FPM/MEPDM(10%)的热分解活化能分别为251.74、244.98和219.60kJ·mol-1;热分解反应级数n均为0.95.随着失重百分率的增大,热分解活化能增大.

The thermal degradation behaviors of fluoroelastomer and the blends of fluoroelastomer/MEPDM were investigated by thermogravimetry （TG） and derivative thermogravimetry （DTG）. The kinetic parameters were evaluated by differential method and integral method. The results showed that the fluoroelastomer/MEPDM blends had higher thermal degradation temperature, but smaller apparent activation energy E than FPM, the E values were 251.74, 244.98, and 219.60 kJ·mol^-1 for FPM, FPM/MEPDM（5%）, and FPM/MEPDM（10%）, respectively. The thermal decomposition reaction order was 0.95 for both FPM and FPM/MEPDM blends. The thermal decomposition apparent activation energy E increased with increasing mass fraction loss a. The TG and DTG results suggested that the FPM/ MEPDM blends had excellent thermalstability. The kinetic data indicated that the FPM/MEPDM blends decomposed easily than FPM after onset degradation temperature.