The Study On Toughening And Reinforcement Of PC/PBT Ccomposite

Polycarbonate (PC) and poly(butylene terephthalate)(PBT) are both engineeringthermoplastics with excellent comprehensive properties. Their blend exhibit high mechanicalstrength and heat defletion temperature, as well as good solvent resistance, wearingresistance, stress crack resistance, dimensional stability and processing fluidity, thus havingwide use. However, PC/PBT blend has low ductility due to the lack of compatibility, and itsstrength and stiffness need further improvement. Therefore, the research on toughening andreinforcement of PC/PBT composite is of importance.In this paper, a series of PC/PBT blends was prepared by melting extrusion. Effect ofPC/PBT proportion on mechanical properties, heat deflection temperature, melt index andrheological properties of the blends were studied. The results showed that as PBT contentintroduced, processing fluidity of PC was improved significantly, with ductility and heatdeflection temperature declining evidently. On this basis, PC/PBT blend of50/50proportionwas studied on toughening and reinforcement.A tough resin, named AES, and three vinyl-acrylic ester elastomers, includingE-MA-GMA, E-MA-MAH and E-BA, were separately used to toughen PC/PBT (50/50)blend, and a series of toughened PC/PBT blends was prepared by melting extrusion. Effect oftoughening agents’ content on mechanical properties, heat deflection temperature and meltindex of the blends were studied. Glass transition temperature, crystallization behavior andmicro morphology were analyzed by DSC, DMA and SEM. It was found that a littletoughening function was seen on AES, while E-MA-GMA, E-MA-MAH and E-BA showedsignificant compatibilizing and toughening effect on PC/PBT (50/50) blend. When content ofthe elastomers was6wt%, notched impact strength of the blends could reach650to820J/m,which was8to10times higher than the pure PC/PBT blend, while strength and modulusdecreased to a certain extent.Halloysite nanotubes (HNTs) and glass fiber (GF) were separately used to reinforcePC/PBT (50/50) blend and PC/PBT/E-MA-GMA (47/47/6) blend by melting extrusion. Effectof content of HNTs and GF, as well as sort, content and modifying methods of couplingagents on mechanical properties, heat deflection temperature and melt index of the composites was studied. HNTs and GF reinforced PC/PBT (50/50) blend and PC/PBT/E-MA-GMA(47/47/6) blend to different extent, respectively. Properties, such as tensile strength, flexuralmodulus and so on, were improved significantly, while ductility lowered evidently. Thereinforcing function of GF was better than HNTs. A certain modifying effect was seen inPC/PBT/HNTs(50/50/10) blend when0.3wt%of KH560was added.