摘要
目的 研究低温环境对硅橡胶性能的影响。方法 探究硅橡胶6141和6144在-55℃长期低温环境下的压缩永久变形性能变化规律,以及不同低温环境对2种硅橡胶邵氏硬度和拉伸性能的影响,并通过DSC和TMA对材料热效应和弹性恢复行为进行分析。结果 在-55℃的低温环境下,随着时间的延长,硅橡胶的低温压缩永久变形会发生突变。当低温持续时间达到27 d后,硅橡胶6141和6144的低温压缩永久变形分别达到81%和92%,出现失效。对比-25℃和-55℃低温环境下的硬度和拉伸性能发现,随着温度的降低,材料拉断伸长率先增加、后降低,拉伸强度和硬度逐渐增大。当温度降低到-55℃时,由于材料产生结晶,硅橡胶6141和6144的拉伸强度分别增大58%和72%,稳定后的硬度值分别增加25和36。通过DSC和TMA研究发现,硅橡胶会在低温下产生结晶,回弹性降低。在-55℃低温环境下,通过TMA测试得到的6141和6144压缩永久变形分别为60%和62%。结论 在长时间的极端低温环境下,硅橡胶会缓慢发生结晶,使硅橡胶材料在高于其玻璃化转变温度和结晶温度范围内出现性能突变,发生失效。
The work aims to explore the effects of low temperature environment on properties of silicone rubber.The change rules for compression set properties of 6 141 and 6 144 silicone rubber were studied,the effects of different low temperature environments on the Shore hardness and tensile properties of two types of silicone rubber were explored,and the thermal effects and elastic recovery behaviors of the materials were analyzed by DSC and TMA.The study suggested that at-55 ℃,with the extension of the freezing time,the low temperature compression set of silicone rubber would change abruptly.When frozen for 27 days,the low temperature compression set of 6141 and 6 144 reached 81% and 92% respectively.Comparing the hardness and tensile properties at -25 ℃ with that at -55 ℃,it was found that with the decrease of temperature,the elongation at break of the material first increased and then decreased,and the tensile strength and hardness gradually increased.When the temperature decreased to -55 ℃,due to crystallization of the material,the tensile strength of silicone rubber 6141 and 6144 increased by 58% and 72%,respectively,and the hardness after stabilization increased by 25 and 36,respectively.Moreover,through DSC and TMA studies,it was found that silicone rubber would crystallize at low temperature,and the resilience would be reduced.And the compression set of 6141 and 6144 obtained by TMA test at -55 ℃ was 60% and 62%,respectively.The results show that,silicone rubber material has a sudden property change and failure at temperature higher than the glass transition temperature and crystallization temperature because the silicone rubber slowly crystallizes in a very low temperature environment for a long time.
作者
胡涛
吴洋
孙茂钧
李茜
赵方超
王玲
HU Tao;WU Yang;SUN Mao-jun;LI Qian;ZHAO Fang-chao;WANG Ling(Southwest Institute of Technology and Engineering,Chongqing 400039,China;CSGC Key Laboratory of Ammunition Storage Environmental Effects;National Field Scientific Observation and Research Station for Atmospheric Material Corrosion in Mohe,Heilongjiang Mohe 165300,China)
出处
《装备环境工程》
CAS
2023年第4期33-39,共7页
Equipment Environmental Engineering
关键词
硅橡胶
低温环境
压缩永久变形性能
拉伸性能
结晶
热分析
silicone rubber
low temperature
compression set
tensile property
crystallization
thermal analysis
