合成乳胶海绵的热老化行为研究

Study on Thermal Aging Behavior of Synthetic Latex Sponge

采用加速老化试验对合成乳胶海绵的热老化行为进行研究,考察了其热氧老化前后的表面形貌、黄度和白度指数、交联密度及傅里叶红外光谱。结果表明:随着老化时间的延长,合成乳胶海绵的多孔结构被破坏,当老化时间为48 d时,合成乳胶海绵部分大孔结构被破坏,其他孔结构完整;老化48 d后,合成乳胶海绵的黄度指数由11.74增大至42.73,白度指数由88.38减小至77.81,黄度变化大于白度变化;由黄度指数和白度指数表征的合成乳胶海绵老化速率分别为0.7023和0.2272 d^(-1);由交联密度表征的合成乳胶海绵老化速率为2.7082×10^(-5) mol·cm^(-3)·d^(-1);在热氧老化过程中,合成乳胶海绵发生了加成和氧化反应。

The thermal aging behavior of synthetic latex sponge was studied by an accelerated aging test,and the surface morphology,yellowness and whiteness index,crosslinking density and FTIR spectra before and after thermal-oxidative aging were investigated.The results showed that with the prolongation of aging time,the porous structure of the synthetic latex sponge was gradually destroyed.Specifically,when the aging time was 48 d,part of the macroporous structure of the synthetic latex sponge was destroyed and other pore structures were intact.After aging for 48 d,the yellowness index of the synthetic latex sponge increased from 11.74 to 42.73,the whiteness index decreased from 88.38 to 77.81,and the change of yellowness was greater than the change of whiteness.The aging rates of synthetic latex sponge characterized by yellowness index and whiteness index were 0.7023 and 0.2272 d^(-1),respectively.In addition,the aging rate of synthetic latex sponge characterized by crosslinking density was 2.7082×10^(-5) mol·cm^(-3)·d^(-1).During the thermal aging process,the synthetic latex sponge underwent addition and oxidation reactions.