湿凝固胶片悬挂时间对天然橡胶性能的影响

Effect of Suspension Time of Wet Solidified Film on Performance of NR

研究乙酸凝固和自然凝固所得湿凝固胶片悬挂时间对天然橡胶性能的影响。结果表明:随着湿凝固胶片悬挂时间的延长,湿凝固胶片的热风干燥所需时间缩短,生胶的氮含量减小,凝胶含量、交联密度和门尼粘度增大;混炼胶的正硫化时间(t90)先缩短后稳定;自然凝固硫化胶的拉伸强度变化不大,拉断伸长率先提高后下降,湿凝固胶片悬挂时间超过12 d后乙酸凝固硫化胶的拉伸强度下降,拉断伸长率变化不大。与乙酸凝固的湿凝固胶片相比,自然凝固的湿凝固胶片的热风干燥时间略长,生胶的氮含量较小,凝胶含量、交联密度和门尼粘度较大,硫化胶的拉伸强度较高。

The effect of the suspension time of the wet solidified film obtained by acetic acid coagulation and natural coagulation on the performance of natural rubber(NR)was studied.The results showed that with the extension of the suspension time of the wet solidified film,the hot air drying time of the wet solidified film was shortened,the nitrogen content of the raw rubber decreased,and the gel content,crosslinking density and Mooney viscosity increased.The t90 of the compound was shortened at first and then stabilized.The tensile strength of the vulcanizate obtained by natural coagulation changed little,the elongation at break increased at first and then decreased.The tensile strength of the vulcanizate obtained by acetic acid coagulation decreased after the suspension time of the wet solidified film exceeded 12 d,and the elongation at break changed little.Compared with the wet solidified film obtained by acetic acid coagulation,the hot air drying time of the wet solidified film obtained by natural coagulation was slightly longer,the nitrogen content of the raw rubber was smaller,and the gel content,crosslinking density and Mooney viscosity were larger,and the tensile strength of the vulcanizate was higher.