氢化丁腈橡胶高温力学性能研究

Mechanical Properties of HNBR at High Temperature

研究高温下不同炭黑用量的氢化丁腈橡胶(HNBR)的回弹值、邵尔A型硬度、拉伸强度、拉伸应力松弛性能和动态力学性能等,分析温度对橡胶分子链段和物理交联网络等微观运动和微观结构的影响。结果表明:随着温度从25℃升高至150℃,不同炭黑用量的HNBR硫化胶的邵尔A型硬度和拉伸强度逐渐减小,回弹值先增大后减小,应力松弛速率增大,应变扫描前后储能模量之差减小;炭黑用量越大,高温下HNBR硫化胶的拉伸强度保持率越大,应力松弛的平衡应力占比越小;温度升高会破坏炭黑补强HNBR硫化胶的填料网络结构,导致结合胶含量减少,HNBR硫化胶高温下的力学性能下降。

The resilience,shore A hardness,tensile strength,tensile stress relaxation and dynamic mechanical properties of hydrogenated nitrile rubber(HNBR)with different addition levels of carbon black at high temperature were studied.The effects of temperature on the micro motion and microstructure of rubber molecular chain segments and physical crosslinking network were analyzed.The results showed that with the increase of temperature from 25℃to 150℃,the shore A hardness and tensile strength of HNBR vulcanizates with different addition levels of carbon black decreased gradually,the resilience first increased and then decreased,the stress relaxation rate increased,and the difference of storage modulus before and after strain sweep decreased.When the addition level of carbon black increased,the tensile strength retention rate of HNBR vulcanizates at high temperature increased,and the proportion of equilibrium stress after stress relaxation decreased.The increase of temperature broken the filler network structure,resulting in the decrease of bound rubber content and mechanical properties of HNBR vulcanizates at high temperature.