原位合成丙烯酸钠改性三元乙丙橡胶制备吸水膨胀橡胶

通过氢氧化钠(NaOH)和丙烯酸(AA)的中和反应，在三元乙丙橡胶(EPDM)中原位合成丙烯酸钠(NaAA)，并在有机过氧化物的作用下将所得混炼胶进行硫化。比较了原位生成NaAA、直接添加NaAA和直接添加聚丙烯酸钠(PNaAA)等三种不同制备吸水膨胀橡胶方法对混炼胶硫化性能和硫化胶吸水膨胀性能的影响，主要研究了原位合成NaAA改性EPDM混炼胶的硫化特性和硫化胶的吸水膨胀性能及其力学性能。结果表明，原位合成NaAA改性EPDM的性能优于直接添加NaAA或PNaAA的EPDM，它不但具有良好的力学性能，而且还具有良好的吸水膨胀性能；随着NaAA含量的增大，硫化速度、硫化程度和吸水膨胀性能均有提高；吸水膨胀橡胶，在NaAA为30质量份时，力学性能具有最大值。过氧化二异丙苯(DCP)用量增大，吸水膨胀率下降，但仍可提高硫化胶的力学性能。

Water-swelling rubber of ethylene propylene diene monomer modified by in situ formed sodium acrylate

Sodium acrylate (NaAA) was in situ prepared in ethylene propylene diene monomer (EPDM) matrix through neutralization of sodium hydroxide and acrylic acid during mixing. The obtained compounds were vulcanized with dicumyl peroxide (DCP). The effects of the approach of preparation on the properties of the EPDM compounds and vulcanizates were studied. The curing characteristics, water-swelling and mechanical properties of EPDM modified by in situ formed NaAA were investigated. The results showed that the properties of the EPDM modified by in situ formed NaAA were better than directly addition NaAA or PNaAA. The in situ formed NaAA could improve the mechanical properties and the water-swelling properties of the EPDM/NaAA vulcanizates. The curing rate, water swelling and mechanical properties of the EPDM/NaAA increased with increasing NaAA amount. The water-swelling ratio decreased, but the mechanical properties improved with increasing DCP content .