环氧化天然橡胶的合成与表征

SYNTHESIS AND CHARACTERIZATION OF EPOXIDISED NATURAL RUBBER

采用过氧化氢在甲酸存在条件下对天然橡胶胶乳进行环氧化反应 .实验表明 ,较适当的反应条件为 :反应温度 30℃ ,初始干胶含量为 30 % ,初始 pH值为 2 .0 ,H2 O2 ,HCOOH与NR干胶之摩尔比为1∶0 .5 5∶1.分别采用了红外光谱 (IR)、核磁共振 (1HNMR)和化学滴定等手段对天然橡胶的环氧化含量进行了表征 .

Latex stage epoxidation of natural rubber with in situ formed performic acid was studied under different feed composition and reaction temperatures. It was approved when reaction temperature was 30℃, the dry rubber content was 30%, pH 2.0, the mole ratio of hydrogen peroxide, formic acid and NR was 1∶0.55∶1, the epoxidation could occur without side reaction. A comparative analysis of the epoxide content of ENR by IR, 1H NMR and titrimetric technique had been made.