The effects of stearic acid on curing characteristic parameters of EPDM blend,dynamic properties,the content of de-composition products of dicumyl peroxide(DCP) and stearic acid in EPDM vulcanizates,the crosslink density of EPDM vulcanizates were investigated respectively by vulcameter,senior extension rheometer,GC and balanced swelling method. The influence mecha-nism of stearic acid on crosslinking of EPDM rubber was studied. The results show that stearic acid reduces the crosslinking efficien-cy of DCP without adding metallic oxide. With the increasement of stearic acid,there is no obvious change of processing optimum curing time t90 ,the crosslink density linearly decreases,and the initial elastic modulus decreases,but the viscous modulus and loss factor increase. And there is no obvious change ofα-acetophenone,α,α-phenyl dimethyl carbinol which are the decomposition prod-ucts of DCP,both the residuces and consumption of stearic acid increase. With the adding of MgO or ZnO,stearic acid in EPDM vulcanizates disappear,and the crosslinking efficiency of DCP increases.%用硫化仪、高级扩展流变仪、气相色谱仪及平衡溶胀法，分别研究了硬脂酸用量对EPDM混炼胶硫化特性参数、硫化胶动态力学性能、DCP热解产物及硬脂酸含量和交联密度的影响，并探讨了硬脂酸对EPDM橡胶交联影响机理。研究结果表明，未添加金属氧化物时，硬脂酸降低DCP交联效率。随硬脂酸用量增加，正硫化时间t90无明显变化，交联密度呈线性降低，初始弹性模量降低，粘性模量和损耗因子提高，DCP热解产物α，α-二甲基苄醇和α-甲基苯乙酮含量无明显变化，而硬脂酸残留量和消耗量均升高；添加氧化锌或氧化镁后，硫化胶中硬脂酸消失，DCP交联效率提高。
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