Study On Quick-Water-Soluble Packing Membrane Of PVA

Poly(vinyl alcohol) (PVA) was modified based on Michael addition, then the water-soluble membranes were prepared with modified PVA as main raw material. It was found that the dissolving capacity and the melt point of these membranes were influenced by several main factors such as water, acrylamide, alkali, temperature and reaction time of this system, which were investigated systemically in this work. The effects of the ratio of PVA and acrylamide and the amount of alkali on the dissolving capacity and the moisture absorption were studied in detail. The main findings are as follows:(1)PVA was modified with acrylamide at alkaline condition by Michael addition reaction, we could obtain the corresponding modified product successfully which had favorable quick-water-soluble property.(2) Before the reaction was proceeded, PVA\acrylamide\sodium hydroxide were mixed at the ratio of ll:l:6,then the mixture was firstly stirred at 80 ℃ for 8 hours, finally the viscous slurry was neutralized by hydrochloric acid. As a result, we could get polymer product which had the best water-solubility.(3) When acrylamide modified PVA solely, the quick-water-soluble ability of the resulting membrane was excellent, but the moisture absorption was too much.(4) After modification, the result product was blended with 10% to 20% of PVA-1788, then a membrane was made by casting the viscous solution onto a PS-slab. This process brought the membrane with nicer quick-water-soluble property, reduced its moisture-absorption rate and improved its dimensional stability.(5) The experiment result showed that the prepared membrane at this condition which could dissolve quickly in water ranging from 5℃ to10C between 30 seconds and 60 seconds, which only had 20% to 30% of moisture-absorption rate at such high humid circumstance as 95% of relative humidity(RH) at 25C, and at one time which had better dimensional stability and mechanics intensity.(6) We anticipated the prepared membrane material could be used in unit packing of non-hydrous chemical reagent such as wash, powdery pesticide, organic pesticide, printing ink and etc.(7) The raw material used by this water-soluble membrane had all made in our own country, so this item had a bright future of industrialization.(8) The result of study had independent knowledge property right.