【摘要】 通过对丁基橡胶密封材料的老化试验研究以及老化试验前后材料的宏观力学性能与微观结构和性能研究,分析老化引起材料内部的分子结构、自由体积等微观结构变化,建立材料结构和性能的关系,从而实现橡胶密封材料老化机制研究。结果表明,宏观上,老化可使丁基橡胶力学性能变差,在适用温度范围内,力学性能变化遵从时间-温度叠加原则;微观上,丁基橡胶存在微量结晶,含有无机晶体添加剂,老化对其晶相结构影响不明显。热氧老化温度较低时,丁基橡胶以氧化交联为主,橡胶材料的密封性能变好;热氧老化温度较高时,丁基橡胶以大分子断链为主,橡胶材料的密封性能变差。小剂量辐照使丁基橡胶发生交联,密封性能变好;大剂量辐照使丁基橡胶发生断链,密封性能变差。更多还原

【Abstract】 By ways of the aging experiments of butyl rubber sealing materials,and by investigating the macroscopic mechanical properties,microscopic structure of butyl rubber before and behind the aging experiments,the variation of microscopic structure,such as molecule structure,free volume of the materials was analyzed.The relationship of structure and properties was established,and the aging mechanism analysis of butyl rubber was realized.The results show that mechanical properties of butyl rubber deteriorates after aging on a macroscale,the mechanical properties of butyl rubber varys according to time-temperature superposition in a range of suitable temperature,and it shows that there are a few of crystals in butyl rubber on a microscale,aging has no obvious effect on the crystalline structure.Butyl rubber undergoes simultaneous crosslinking and scission during atmospheric aging and irradiation,crosslinking takes advantage of scission in lower temperature and small dose,its sealing properties are improved,and scission takes advantage of crosslinking in higher temperature and large dose,its sealing properties are deteriorated.更多还原