天然胶乳的氢化(英文)

Hydrogenation of natural rubber latex

以水合肼、双氧水和硼酸为催化体系,对天然以水合肼、双氧水和硼酸为催化体系,对天然胶乳进行非贵金属催化的原位母体加氢,并用核磁共振氢谱对氢化天然胶乳的结构进行表征。结果表明,氢化度随着硼酸用量的增加而增大,当硼酸/碳碳双键(摩尔比)达到0.25时,天然胶乳的加氢度接近60%

Hydrogenation is a potential method offering polymer which can not be prepared by a simple and conventional polymerization^[1.2]. Natural rubber has been known containing highly eis-1,4-polyisoprenic structure, so it has primary drawbacks in thermal and oxidative stabilities as well as poor oxygen and ozone resistance due to the presence of the unsaturated bonds along polymer main chain. Hydrogenation can overcome these drawbacks without effecting on its glass transition temperature^[3]. In this study, natural rubber latex was hydrogenated at ambient pressure, and catalyzed by hydrogen peroxide/hydrazine hydrate redox system in the presence of boric acid. The effects of mole ratio of hydrogen peroxide/hydrazine hydrate and boric acid/carbon-carbon double bonds on degree of hydrogenation were investigated as shown in Fig 1 and Fig 2.