用橡胶加工分析仪(RPA)分析硫化程度对未硫化天然橡胶(NR)的动态性能影响。结果表明,不同硫化程度的混炼胶储能模量随硫化时间的增加而增加,损耗因子降低,NR在0.8倍的正硫化时间(t90)时储能模量最大,损耗因子变化最小。交联密度(Mc)和/△G'(△G’=G’max-G’min)的值随硫化时间的增加而增大,当体系Mc增大时,△G’也随之增大,说明交联网络和粒子网络存在相互作用。由扫描电镜(SEM)图可以看出,在0.8倍的正硫化时间,交联网络与粒子网络相互作用明显,进一步验证了粒子网络和交联网络之间的相互影响。
The influence of the different vulcanizating time on the dynamic properties of Nano-Ca CO3/NR composite was discussed in this paper. The results measured by RPA showed that the storage modulus of NR compound was increased with the vulcanization time increasing, but the loss factor (tan 8) was decreased inversely. At 0. 8 times of t90, storage modulus was maximum, loss factor change was the least. Mc (M, is crosslinking density)and △G' were increasing with the increase of vulcanization time. △G'rwas also increasing with the crosslinking density increasing. It can be found that there was an interaction between crosslinking network and particle network. Imagines of SEM of rubber compound exhibited that the interaction between fillers and rubber was rather obvious at the 0. 8 times of tg0 and could further confirmed the close relationship between crosstink network and uarticle network.