环氧化天然橡胶制备反应动力学

采用适当提高反应温度、减小甲酸和过氧化氢用量的方法制备不同环氧化程度（Ｂ）的环氧化天然橡胶（ＥＮＲ），并利用质量作用定理，从ＥＮＲ的制备基本反应式推导出ＥＮＲ的制备反应动力学方程，讨论了Ｂ与反应温度和时间及甲酸、过氧化氢用量的关系。结果表明，用过氧甲酸对ＮＲ进行环化改性制备ＥＮＲ的反应为二级反应，对ＮＲ和过氧化氢的反应则为一级反应。求出的反应速率常数ｋ４为１１２５×１０－４ｄｍ３·（ｍｏｌ·ｓ）－１，活化能为８２６７４ｋＪ·ｍｏｌ－１；Ｂ与过氧化氢用量之间为线性关系

Kinetics of Epoxidized Natural Rubber Preparation

The epoxidized natural rubbers (ENRs) with different epoxide numbers (B) were prepared by suitably increasing the reaction temperature and reducing the formic acid and hydrogen peroxide,the equation of reaction kinetics in ENR preparation was derived from the basic reaction equation and the relationship of B to reaction temperature and time,formic acid and hydrogen peroxide level was discussed.The results showed that the reaction in ENR preparation by epoxidizing NR with formic acid peroxide was the first order reaction,and the reaction of NR with hydrogen peroxide was the second order reaction.The resultant reaction rate constant k4 was 1.12510-4 dm3(mols)-1,activation energy was 82.674 kJmol-1;the relationship between B and hydrogen peroxide was linear.