用橡胶加工分析仪测定过氧化物硫化三元乙丙橡胶的交联密度

摘要

利用橡胶加工分析仪(RPA)测得二(叔丁基过氧化异丙基)苯(BIPB)硫化三元乙丙橡胶(EPDM)的硫化曲线，依据理想橡胶弹性方程计算得到 EPDM 硫化胶的交联密度，并与平衡溶胀法和单轴拉伸法测得结果进行了比较。结果表明，由平衡溶胀法、单轴拉伸法和硫化曲线法测得 EPDM 硫化胶的交联密度呈现相似的变化规律，即交联密度随着 BIPB 用量的增加而增大，但又因分子链缠结不同而存在差异；平衡溶胀法与硫化曲线法测得 EPDM 硫化胶的交联密度相关性比较好，因而利用 RPA 测定硫化胶的交联密度是可行的。%Based on the ideal rubber elasticity equation, crosslink density of di(tert-butylperoxyiso-propyl) benzene ( BIPB) cured ethylene-propylene-diene monomer ( EPDM) was calculated from cure curves measured by rubber process analyzer (RPA), and the measured results were compared with those measured by equilibrium swelling method and stress-strain method. The results showed that the values of crosslink density obtained by above-mentioned 3 methods all increased with increasing content of BIPB, exhibiting a similar change trend, however, there were difference among the data by the 3 methods owing to the different extents of entan-glement. But those from equilibrium swelling and cure curve methods had a good correlation, so that RPA cure curve method was available to measure crosslink density.