Studies On Volume Expansion Type Plasticized Polyvinyl Chloride

Water-swellable rubber (WSR) is a kind of functionally watertight rubber with elastic sealing and water-swellable properties. WSR is regarded as a good waterproof and sealing material for its lots of merits, such as facile construction, high efficiency, cost reduction and so on. The usual methods used to prepare WSR are mechanical mixing and chemical grafting using rubber as matrix. Among them, the blending is a easy way to prepare WSR and has been used in industry. But hydrophilic super absorbent resin cannot disperse well in and weakly interacts with hydrophobic rubber matrix so that it can break off from the elastomer network easily. This may weaken water-swellable abilities, mechanical properties and repeated usage. Plasticized PVC has elastomer similar to rubber, and plasticized polyvinyl chloride is low cost, facile processing and without the off-flavor of rubber, so plasticized polyvinyl chloride has wide applications in many fields as the substitute of rubber.In this study, a series of water-swellable elastomers were prepared by blending plasticized polyvinyl chloride (PVC) with starch graft polyacrylate sodium (SZa). The morphology and properties of plasticized PVC/SZa blends were studied by means of water-absorbing ratio, water-swelling ratio, weight loss ratio, tensile stress-strain and SEM tests. The main results are as following: 1. When PVC/SZa blends are pretreated by means of soaking in distilled water,SZa which weakly interacts with the plasticized PVC matrix can be washed out.With the increase of SZa content, the water-absorbing ratio and the...