部分动态预硫化对EPDM发泡行为的影响

The Effect of Partially Dynamic Vulcanization on the Foaming of EPDM

采用部分动态预硫化工艺制备三元乙丙橡胶(EPDM)发泡材料,即通过在哈克中动态预硫化来控制橡胶预交联,然后混入相同的硫化和发泡剂体系并制得发泡材料。研究了部分动态预硫化对EPDM凝胶含量及发泡行为的影响。结果表明,动态预硫化过程中,随硫磺用量增加,其最终平衡扭矩升高,预硫化混炼胶的凝胶含量增加;硫化和发泡行为测量表明,动态预硫化并未影响EPDM混炼胶二次硫化速度以及发泡剂分解速度;扫描电镜(SEM)显示,预硫化阶段硫磺用量为0.0125phr时的试样,能获得较好的泡孔结构和较低的密度,表明适量的预硫化能明显改善EPDM混炼胶的发泡行为。

This study has developed a new way of rubber foam preparation using partially dynamic vulcanization technology.The partially precure in HAAKE is used to control the degree of ethylene-propylene-diene rubber（EPDM） compound pre-crosslinking.The final torque increases with sulphur content increasing,which shows that the crosslink density of precured EPDM compound could be effectively regulated by adding sulphur.The gel content increases with pre-crosslinking degree increasing.Rheometric measurement shows that the rate of vulcanization of partially precured EPDM compound is not affected by the precure in the HAAKE rheometer.The blowing results show that the foam processability could be improved and the expansion ratio increases in the same processing condition for optimum partially precured EPDM compound,which indicates the efficiency of blowing agent azodicarbonamide（AC） could be enhanced.Scanning electron microscope（SEM） results show that the foam articles of optimum partially precured EPDM compound have a regular cell structure.