壳脑酸酯溴化反应性质及在虫胶漂白中的应用

Property of Shellolate Bromination Reaction and Its Application to the Bleaching of Lac Resin

运用紫外分光光度法和波谱分析法研究了壳脑酸酯溴化反应的动力学性质和产物及脱溴产物的结构，结果表明，壳脑酸酯溴化反应是二级反应，反应活化能是６６．４ｋＪ／ｍｏｌ，产物是α，β－二溴壳脑酸酯，该产物的脱溴产物是β－溴壳脑酸酯，从而揭示了α位氯易脱去是白虫胶易变性的原因，在虫胶漂白过程中进行脱氯处理脱去α位氯可延缓白虫胶的变性。

The kinetic property of shellolate bromlnation reaction was investigated by UV spectrophotometry and the structures of the product and its debrominated product were iden- tified by spectral analysis. Results obtained show that the reaction is a second order one, the activation energy is 66. 4 kJ/mol,the product is α,β-dibromoshellolate and its debrominated product is β-bromoshel1olate. Accordingly, α-chlorine, being harmful to the storage of bleached lac. is easier to sp1it off than β-chlorine. If α-chlorine splits off while 1ac resin is bleached, the storage property of bleached lac will be improved.