氯化硫酰-甲缩醛法合成强碱型阴离子交换树脂

<正> 氯甲基苯乙烯-二乙烯苯共聚体(简称氯甲基共聚珠体)的合成,当采用传统的氯甲醚法时,由于混杂有容易致癌的二氯甲醚而不甚妥善.不直接使用氯甲醚的氯甲基化方法,虽已有些专利报道,但并不具体.本文研究氯化硫酰-甲缩醛法制备氯甲基共聚珠体,可在氯化硫酰、甲缩醛、催化剂无水氯化锌用量甚低的情况下,得到氯甲基共聚珠体含氯量稳定在16—17.7％,合成的强碱型阴离子交换树脂的交换当量稳定在3.3—3.5毫克当量/克(干树脂),而且发现甲缩醛中少量甲醇或水的存在对氯甲基化反应影响甚微.

SYNTHESIS OF STRONG BASIC TYPE ANION-EXCHANGE RESIN VIA SULPHURYL CHLORIDE-METHYLAL METHOD

Copolymer beads prepared from styrene and divinylbenzene were chloromethylated by a mixture of sulphuryl chloride-methylal. The chlorine contents of the chloromethylated copolymer beads are found to be 16-17% while the exchange capacities of the strong basic type anion-exchange resin obtained thereof are within the range of 3.3-3.5meq/g (dry resin).The effects of the molar ratio of the raw materials, the amount of zinc chloride catalyst, and the contents of methanol and water in methylal on the chlorine contents of the chloromethylated copolymer beads and exchange capacities of the synthetic strong basic type anion-exchange resin were investigated.In contrast with the traditional chloro methyl methyl ether method better results were obtained by using lower molar ratio of the raw materials and less amount of the catalyst.Methanol and water contents of methylal if present within certain limits have little or no effect on the chlorine content of the beads and exchange capacity of the resin.