橡塑共混材料耐油耐热机理的SEM/XPS研究

Study of Oil/Heat Resistance Mechanism of Rubber-plastic Blends from SEM and XPS Analyses

采用乙烯-乙酸乙烯共聚物(EVA28)改性甲基乙烯基硅橡胶(MVQ),制备了拉伸强度及断裂伸长率优于MVQ、耐油及耐热性较好的橡塑共混材料(MVQ/EVA28);通过扫描电子显微镜(SEM)和X射线光电子能谱(XPS)对共混材料耐热耐油前后表面形貌、元素组成及其化学状态变化进行了表征,研究了耐油耐热机理。结果表明,耐油实验后,EVA组分吸油膨胀率高导致样品表面C元素增多,O及Si元素相对下降;耐热实验后,SiO2迁出使得材料表面C元素减少,O及Si元素相对增多;橡塑共混材料表面元素结合状态的变化及SiO2的迁出是影响其耐油耐热性能的因素。

Rubber-plastic blends were prepared from methyl vinyl silicone rubber(MVQ)and ethylene-vinyl acetate copolymer(EVA28,VA content 28%).They were superior to neat MVQ in tensile strength and elongation at break and also have good oil/heat resistance.The changes of the morphology and the element compositions as well as their chemical state before and after the oil/heat treatments were characterized by scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS).The oil/heat resistant mechanism of the blends was analyzed.XPS showed that C element increased while O and Si element decreased on the surface on resistance test due to the high oil absorption expansion rate of EVA component.C element decreased while Si and O element increased on the surface on heat resistance test for the migration of SiO2 to the surface.