Study On Modification Of Poly (Butylene Succinate) And Thermoplastic Phosphate Starch By Blending

Blending PBS with starch can reduce the cost and maintain the biodegradability of materials.Thermoplastic phosphate starch (TPS) was prepared with phosphate starch as matrix and glycerol, water as plasticizer by melt processing. TPS was modified with organic carboxylic acid, polyvinyl alcohol (PVA) and hyperbranched polyester (HBP) respectively to improve its properties ulteriorly. The influence of TPS content and blending method on properties of PBS/TPS was researched, and the influence of TPS plasticized with sebacic acid on properties of PBS/TPS was also discussed. The influence of TPS modified with PVA and TPS modified with HBP on properties of PBS/TPS was also evaluated respectively.The results show as follows.1) The crystallinity decreased with the glycerol content increased, when the plasticization and the processability increased. It was found that TPS plasticized with organic carboxylic acid had better mechanical properties, and some PVA with lower alcoholysis degree could improve the mechanical properties of TPS. The processability of TPS was improved with increasing glycerol content, when Tg of TPS decreased. The mechanical properties of TPS were good while HBP content was reasonable.2) PBS/TPS blends which were prepared with two-step method had better melt index, elongation at break and impact strength. When TPS content was 10%, the impact strength of blends increased by 34% compared with that of pure PBS, which TPS played a role in toughening as elastomer. Blending PBS with TPS plasticized with sebacic acid, the tensile strength, bending strength, melt index and melting point of blends all increased, and the water absorption decreased compared with that of PBS/TPS. However, its toughness decreased.Both PBS/(TPS-PVA) and PBS/(TPS-HBP) had a better tensile strength compared with that of PBS/TPS. HBP was of special structure which could form strong chemical bonds with PBS and interaction with starch to improve the compatibility between two phases. The toughness of PBS/(TPS-HBP) was better than that of PBS/(TPS-PVA).