海泡石对补强三元乙丙橡胶热氧稳定性的影响

Effect of Sepiolite on Thermo-oxidative Stability Performance of Reinforced EPDM

以表面改性后的海泡石(OSP)作为三元乙丙橡胶(EPDM)的补强填料进行4因素3水平正交试验(L9(3~4)),研究了各因素对改性海泡石补强EPDM复合橡胶(OSP/EPDM)热氧稳定性能的影响。用热重-差热分析(TGDTA)测定了OSP/EPDM氧化峰的峰值温度的变化,根据OSP/EPDM硫化胶的氧化反应和氧化反应动力学计算求得氧化反应表观活化能ΔE和反应速率常数K_T,用Doyle氧化诱导期公式计算了氧化诱导期(OIT),并与橡胶在老化箱中的热老化实验结果比较。结果表明:求得的氧化诱导期t_(70)与反应速率常数K_(70)的结果十分吻合,与橡胶老化箱老化试验实测的老化系数变化的趋势相一致,证明根据t_(70)能很好地评价OSP/EPDM的热氧稳定性。

Effect of the addition of modified sepiolite on the thermal oxidative stability of the surface modified sepiolite reinforced ethylene propylene diene monomer rubber（OSP/EPDM） was investigated via the orthogonal experiment L9（3^4）. The peak temperature variation for the oxidation process of OSP/EPDM is determined by thermogravimetric and differential thermal analysis（TG-DTA）. The apparent activation energy（ΔE） and reaction rate constant（KT） were acquired via oxidation reaction test of the vulcanized rubber and oxidation reaction kinetics calculation, while the oxidation induction time（OIT） was calculated according to Doyle formula, which was compared with the experimental resultsof rubber aging test. The results show that the oxidation induction time（t70） are in good agreement with the reaction rate constant K70, and the calculated results are consistent to the experimental ones, indicating that the t70could be applied to evaluate thermal oxidative stability of OSP/EPDM.