氧化降解天然胶乳制备液体天然橡胶的研究

Study on Preparation of Liquid Nature Rubber by Oxidative Degradation

使用正交试验和单因素试验研究了氧化降解法制备液体天然橡胶时的工艺条件。结果表明,影响降解胶乳相对分子质量的因子主次顺序为反应时间、温度、丙醛用量和引发剂用量。最佳降解条件为引发剂,2份;丙醛,30份;反应条件80℃×24h,得到Mn为1.2×104。随引发剂用量的增加,降解胶乳相对分子质量先下降后上升;随丙醛用量的增加或温度的升高或反应时间的延长,降解胶乳相对分子质量都下降。

The technology conditions of liquid nature rubber prepared by the method of oxidative degradation were studied through the application of orthogonal experiment method and single factor experiment.The results showed that according to their effect on degradation latex molecular weight,the influence factors could be ranked as follows: reaction time,reaction temperature,dosage of propanal and dosage of initiator.The optimum conditions for the degradation were natural rubber latex of 5% dry rubber content,2 phr K2S2O8,and 30 phr propanal,and the reaction condition was at 80℃ for 24 h.The Mn of the rubber could be reduced to 1.2×104.The degradation latex molecular weight first decreased and then increased with the increase of the dosge of the initiator.The degradation latex molecular weight all decreased with the increase of the dosage of propanal or the rise of the reaction temperature or the prolong of the reaction time.