丁腈橡胶/聚乳酸热塑性硫化胶:橡塑比与性能及结构的关系

NBR/PLLA Thermoplastic Vulcanizates:Relationship between Mechanical Properties and Structure with Different NBR/PLLA Ratio

采用动态硫化技术,在双辊开炼机上制备了丁腈橡胶/聚乳酸热塑性硫化胶(NBR/PLLA-TPV)。探索了用NBR与PLLA制备动态硫化热塑性硫化胶的合适配比,制备了橡塑比NBR/PLLA在(7:3)^(4:6)范围内的热塑性硫化胶;重点考察了橡塑比对NBR/PLLA-TPV性能的影响。结果表明:NBR/PLLA的配比在(6:4)^(5:5)范围内制备的热塑性硫化胶具有较好的综合性能,且NBR/PLLA配比为5.5:4.5时综合性能最好。为了深入理解所制备的TPV结构与性能之间的关系,采用DSC对所制备TPV各相的玻璃化转变温度及PLLA在其中的结晶情况进行了研究。DSC数据显示:不同的NBR/PLLA配比下,共混物中NBR与PLLA的ΔTg略有不同,即两者的相容性不同。用TEM对所制得的TPV的形态进行观察,发现不同的NBR/PLLA配比下,随着NBR相对含量的减少,共混物的相形态由以NBR为基体相的海岛结构过渡为双连续结构,最后演变为以PLLA为海相的海岛结构。

We prepared nitrile rubber/poly（lactic acid） thermoplastic vulcanizates（ NBR/PLLATPV） by adopting dynamic vulcanization technology with double roll open mixer successfully. And by changing the ratio of NBR/PLLA from（7：3）～（4：6）, we prepared NBR/PLLA-TPV with different ratio of NBR/PLLA, explored the suitable ratio of NBR/PLLA. At the same time, we focused our research on the infl uence of proportion to properties of NBR/PLLA – TPV. In order to understand the relationship between the structure and properties of NBR/PLLA – TPV, we investigated the crystallization of PLLA and the glass transition temperature of each phase using DSC. Meanwhile, we observed the morphology of the NBR/PLLA – TPV by TEM. And we found that thermoplastic vulcanizates has good mechanical properties with the ratio of NBR/PLLA in the（6：4） ～（5：5）; and when the ratio of NBR/PLLA is 5.5：4.5,TPV has the best mechanical properties.DSC data show that ΔTg of NBR and PLLA different slightly at different ratio of NBR/PLLA, i.e. different compatibility between NBR and PLLA. TEM results show that at the different ratio of NBR/PLLA, the phase morphology of the blends are different—NBR as matrix phase when proportion of NBR is high,then bicontinuous with decreasing the proportion NBR, and fi nally evolved into the island structure with PLLA as matrix.