高阻隔性皂化EVA树脂的研制——Ⅰ.甲醇～水体系

The Development of High Barrier Saponified EVA Resin

本文以碱作催化剂,采用高水含量(>5%)的醇～水皂化体系及均相～非均相皂化工艺,由高VA含量的EVA制备高阻隔性皂化EVA树脂,比较系统地研究了工艺条件与产品皂化度、后处理难易及色泽的关系。结果表明,随碱、醇用量的增大和温度的升高,产品皂化度提高;在碱用量少时,快加EVA产品的皂化度比慢加EVA高;随着碱、醇用量的减少,后处理变难;在碱用量大时,EVA采取慢加的方式后处理容易;反应温度提高,后处理变易;碱用量过大、醇用量太少或温度过高均会使产品色泽变黄;当反应温度等条件适宜时,皂化过程15分钟即可完成;皂化过程完成后;延长时间对产品的后处理难易及色泽无明显影响。

High barrier saponified EVA resin was prepared from high VA content EVA by alcohol-water (water content>5%)saponification system and homogeneous-heterogeneous saponification technology, with alkali used as catalyst. The relations be-tween process conditions, saponification degree, aftertreatment and the color of the product were studied. The results showed thatthe saponification degree increased with the increase of alkali, alcohol and temperature. The degree was higher when addingEVA quickly than that when adding EVA slowly at low alkalicontent. The aftertreatment became difficult as alkali and alcoholcontents decreased. The aftertreatment became easy when adding EVA slowly at high alkali content, and easy, too, at high reac-tion temperature. The color of the product would turn yellow when the alkali content was too high and alcohol content too lowand at too high temperature. The saponification reaction would finish within 15 minutes when the process conditions were prop-erly controlled. The prolongation of the time had no effect on the aftertreatment and color when the saponification reactionstopped.