低硬度动态硫化热塑性弹性体的制备及性能

Low Hardness Thermoplastic Dynamic Vulcanizates

通过反应挤出动态硫化技术,制备得到了高橡塑比(70/30)高充油比(1∶1)的EPDM/PP共混型热塑性动态硫化橡胶(EP-TPV)。分别研究了硫化剂用量、硫化工艺以及纳米CaCO3填充量对低硬度TPV性能的影响。结果表明,随着硫化剂用量的增加,TPV的断裂伸长率、永久压缩形变降低,当硫化剂含量达到6%,助硫化剂含量达到3%时,TPV的总体性能最佳;在硫化剂和助硫化剂用量相同的情况下,采用二次硫化工艺(分步硫化工艺)有助于提高材料的拉伸强度;纳米CaCO3填充剂在TPV中可以起到显著的补强作用。

EP-TPVs based on ethylene propylene diene rubber, polypropylene and oil blends with 70/30/70 （w/w/w） ratios were prepared by a reactive extrusion process. The influence of the curing agent and co-agent dosages, the nano-CaCO3 addtion in the formula system and the dynamic vulcanization procedure were systematically investigated. It is shown that the elongation at break and the compression set of TPV are decreased as the increased dose of curing agent and co-agent in the formula. The optimized dose for the curing system is as following： 6 % curing agent and 3 % co-agent. When the concentrations of curing agent and co-agent are consistent, a two-step curing process can benefit the enhancement of the tensile strength of the resultant TPV materials. Furthermore, introducing nano- CaCO3 in formula can also improve the mechanical properties.