硫黄硫化体系对三元乙丙橡胶硫化特性及硫化胶性能的影响

Effect of sulfur curing systems on curing characteristics and properties of ethylene propylene diene monomer

研究了促进剂与硫黄的质量比(A/S)对硫黄硫化体系三元乙丙橡胶(EPDM)的硫化特性、交联网络结构、动态力学性能以及物理机械性能的影响。结果表明,随着有效硫含量的增加,EPDM混炼胶的焦烧时间和正硫化时间缩短;在有效硫含量相同时,焦烧时间随着促进剂用量的增加而逐渐减小,硫化程度无明显差别。随A/S值增大,EPDM硫化胶的交联密度增大,相应地力学性能得以改善;但促进剂用量较高时交联密度反而下降,A/S为3.7时交联密度达到最佳。动态力学性能分析结果显示,随着单硫和双硫键含量的升高,储能模量下降得越发明显,损耗因子对应变的依赖性越大。

The effect of mass ratio of accelerator to sulfur （ A/S） on curing characteristics , crosslinking network structures , mechanical and dynamic mechanical properties of sulfur curing system based ethylene propylene diene monomer （ EPDM ） was researched.The results showed that with the increase of effective sulfur content , both the scorch time and curing time decreased; at the same effective sulfur content , scorch time was gradually decreased with increasing accelerator.When the A/S increased , the crosslinking density increased , thus correspondingly improving the mechanical properties.On the contrary , much more accelerator decreased the crosslinking density , and the optimum crosslinking density was obtained at A/S 3.7.The analytical results of dynamic mechanical properties indicated that the higher the content of monosulfide and disulfide bonds, the more obvious the decrease of storage modulus , and the stronger the dependence of loss factor on strain.