用甲基丙烯酸原位改性纳米CaCO_3填充三元乙丙橡胶 Ⅱ.纳米CaCO_3用量的影响

Ethylene-propylene-diene rubber filled with nano-CaCO_3 in-situ modified by methacrylic acid Ⅱ. Effect of nano-CaCO_3 amount

使用甲基丙烯酸(MAA)原位改性纳米CaCO3填充三元乙丙橡胶(EPDM),制备了纳米CaCO3增强EPDM硫化胶。考察了纳米CaCO3用量对EPDM硫化性能和力学性能的影响。此外,还对EPDM的应力-应变曲线和应力弛豫行为进行了研究。结果表明:加入纳米CaCO3缩短了EPDM的焦烧时间,降低了硫化速率,混炼胶的转矩增量逐渐增大;MAA的引入使相同纳米CaCO3用量下混炼胶的转矩增量稍有下降;随着纳米CaCO3用量的增加,EPDM的拉伸强度、定伸应力、撕裂强度和邵尔A硬度均逐渐提高;加入MAA,不同程度地提高了EPDM的拉伸强度、定伸应力和撕裂强度,对邵尔A硬度则无显著影响。

Ethylene-propylene-diene rubber （EPDM） was filled with nano-CaCO3 which was insitu modified by methaerylie acid （MAA）. The effect of nano-CaCO3 amount on cure characteristics and mechanical properties of EPDM were investigated. Furthermore, the stress-strain curves and stress relaxation behavior of EPDM vulcanizates was also studied. The results showed that the filler reduced the scorch time and cure rate index of EPDM, meanwhile increased the torque increment （AT）. The addition of MAA reduced AT slightly at the same filler amount. With the filler amount increased, the tensile strength, modulus, tear strength and Shore A hardness all increased. The additions of MAA further increased the tensile strength, modulus and tear strength, and had no obvious effect on Shore A hardness of EPDM vulcanizates.