助交联剂对三元乙丙橡胶过氧化物硫化的影响

Influence of co-agents on peroxide vulcanization of ethylene propylene diene monomer

分别采用三烯丙基异氰脲酸酯(TAIC)、三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)以及高乙烯基聚丁二烯(HVPBd)作为过氧化物硫化三元乙丙橡胶(EPDM)的助交联剂,研究其对EPDM胶料硫化特性及硫化胶力学性能的影响。结果表明,3种助交联剂的添加能明显促进硫化程度,硫化胶的硬度和定伸应力均明显提高,添加TAIC的EPDM混炼胶硫化程度最高,但添加TMPTMA使胶料的焦烧安全性变差,而添加HVPBd的EPDM胶料降解程度最低。通过一级动力学模型及自催化反应模型研究EPDM硫化动力学行为时发现,助交联剂类型影响胶料的硫化反应速率,其中TMPTMA能明显促进硫化反应速率,TAIC次之,而HVPBd几乎没有影响,但硫化反应表观活化能由于助交联剂的添加均出现降低,其中添加TAIC胶料的表观活化能最低。

The influences of three kinds of coagent,such as triallylisocyanurate（ TAIC）,trimethylol propane trimethacrylate（ TMPTMA） and high vinyl poly（ butadiene）（ HVPBd）,on curing characteristics of ethylene propylene diene monomer（ EPDM） compounds with peroxide as vulcanizator,and mechanical properties of EPDM vulcanizates were investigated.The results showed that the introduction of TAIC,TMPTMA and HVPBd co-agents could significantly promote the curing degree and improve the hardness and tensile modulus of EPDM vulcanizates.Moreover,the EPDM compound with TAIC had the highest curing degree,that with TMPTMA had poor scorch safety,and that with HVPBd had the lowest degradation degree.The kinetic results obtained by the first-order kinetic model and auto-acceleration reaction kinetic model indicated that the co-agents with different molecular structures had different effects on curing reaction rate,in which TMPTMA could promote the curing reaction rate significantly,TAIC secondly,while HVPBd had little effects on it.However,the introduction of the co-agents,all decreased the apparent activation energy of vulcanization reaction respectively,and the EPDM compound with TAIC exhibited the lowest activation energy.