不同天然胶乳含量乳胶海绵材料的热空气老化行为

Hot air aging behavior of rubber latex foams materials with different natural rubber latex content

采用加速热空气老化方法对5种不同天然胶乳含量的乳胶海绵进行研究,通过老化动力学模型及黄度指数、白度指数、交联密度等指标对老化程度和老化速率进行表征,并探究材料的热空气老化行为。结果表明,在老化过程中,黄度指数随老化时间的延长而增加,白度指数随老化时间的延长而降低,交联密度在老化进程的前、中期阶段增加速率较快,后期阶段增加速率则有所变缓。通过对乳胶海绵动力学模型分析可知,在老化过程中天然胶乳质量分数为80%的乳胶海绵的老化反应速率最大,天然胶乳质量分数分别为50%、40%和0的乳胶海绵老化速率较为接近,从而表明天然乳胶含量低的乳胶海绵的热空气老化性能较好。

Five kinds of rubber latex foams with different natural rubber latex content were studied by the accelerated hot air aging method,and the aging degree and aging rate were characterized by aging kinetic model and several performance parameters,such as yellowness index,whiteness index,cross-linking density.In addition,the hot air aging beha-viors of rubber latex foams were explored.The results showed that yellowness index increased and whiteness index decreased with the increase in the aging time during the aging process.The cross-linking density increased at a faster rate in the early and middle stages of the aging process,and increased at a relatively slower rate in the later stage of the aging process.The analysis of kinetic model of the rubber latex foams indicated that the aging reaction rate of the rubber latex foams with natural rubber latex mass fraction of 80%was the largest during the aging process,and the aging reaction rates of the rubber latex foams with natural rubber latex mass fraction of 50%,40%and 0 were relatively close,which demonstrated that the rubber latex foams with low natural rubber latex content had better hot air aging performance.