Preparation and Properties of Volume Expansion Type Blends of Plasticized Polyvinyl Chloride/Starch Graft Polyacrylate Sodium

A series of water-swellable elastomers were prepared by blending plasticized polyvinyl chloride (PVC) with starch graft polyacrylate sodium (SZ_A). The morphology and properties of PVC/SZ_A blends were studied by means of water absorbing ratio, water swelling ratio, weight loss ratio, tensile stress-strain and SEM tests. The results indicate that when PVC/SZ_A blends were pretreated by means of soaking in distilled water, SZ_A, which weakly interacts with the PVC matrix can be washed out. After the pretreatment, the blends were quite stable in water, the water absorbing ratio of the blends increased and the water swelling ratio of the blends nearly was unchanged in the further water absorbing tests. The mechanical properties of the pretreated blends slightly reduced as compared to those of the without pretreatment. With plasticizer content of the plasticized PVC in the blends, the water absorbing ratio and the water swelling ratio increased.