热氧老化对氯丁橡胶交联密度和力学性能的影响

摘要

The equilibrium swelling method was used to study the influence of thermal-oxidative aging on crosslink density and mechanical properties of CR.The results showed that with aging time prolonged,crosslink density increased firstly and then decreased,the higher the temperature,the more obvious the increase;the variation trends of tensile strength and 100％ constant tensile stress were same compared with crosslink density changed,the breaking elongation decreased rapidly and then tended to a constant value,and the hardness increased gradually.Under the thermal-oxidative aging conditions,crosslink reaction occurred between the molecules inside of the CR,produced the crosslinking bond,crosslink density increased;the macroscopic mechanical properties showed different trends.%采用溶胀法研究了热氧老化对氯丁橡胶(CR)交联密度和力学性能的影响.结果表明,随着老化时间的延长,CR交联密度先增大后减小,温度越高增幅越明显;拉伸强度和100％定伸应力变化趋势与交联密度相近,拉断伸长率快速降低后趋于定值,硬度逐渐增加.热氧老化条件下,CR内部大分子之间发生交联反应,产生交联键,交联密度增加,力学性能由此表现出不同的变化趋势.