Study On Recycled PET Modified By Increasing Its Viscosity And Prepared To Be Engineering Plastics

Polyethylene terephthalate mainly used for fiber production, and PET in the field of application of non-fiber is manufactured beverages, food containers and packaging films, especially the production of beverage bottles are greatly developed in recent years. Almost all the bottles are prepared by the PET resin from its consumption to 10% per annum rate of rapid growth. At the same time, it has brought white pollution generated by PET waste bottles. The percentage of recyceled PET bottle films "escalation of use" for the high-performance engineering plastics is only about 8.4 percent. PET bottle recycling research and development of the re-use of new technologies, prepared by high-performance, low-cost rPET engineering plastics is conducive to the comprehensive utilization of resources and reduce environmental pollution; while for the technology itself, it can open up new economic growth Points. The main research and the results are as follows:(1) This thesis studied that recycled PET was modified with pyromellitic dianhydride(PMDA) to achieve a chain extension which was characterized by intrinsic viscosity and carboxyl value. The thermal and crystallizing behavior was studied by DSC. The results showed that Pyromellitic dianhydride has a good chain extension, and when the content of PMDA is 1.25%, intrinsic viscosity of rPET is 0.813dL/g , which has reached the using request of engineering plastics; and also has an effect on crystallizing behavior of PET.(2) The thesis studied PC was modified by rPET and its blending alloy. Polyolefin elastomer ethylene - methacrylate - glycidyl methacrylate (E-MA-GMA) is used to toughen and compatibilize the PC/rPET alloy. When the content of E-MA-GMA is 7.5%, the blend changes in brittle-ductile, notched impact strength and tensile strength were 58.76kJ/m2 and 52.40 MPa, showing high-strength toughness. When the content of elastomer increases to 15%, the tensile strength dropped to 44.74MPa. SEM study found, E-MA-GMA as the reaction of compatibilizer, dispersed PET particles thinner. With the content of E-MA-GMA increasing, PET in the PC/PET/E-MA-GMA blends shows a very irregular structure similar to strip or flake.(3) The thesis studied the mechanical properties and thermal properties of rPET composite material which was modified by glass fiber and nucleating agent. First of all, the test inspected the effect of the contents of glass fiber on the composite material's mechanical properties, thermal properties and crystallizing behavior. Then a rare earth-like of nucleating agent is used to improve the mechanical properties and thermal properties of the composite material. Study found that the higher glass fiber content, the mechanical properties and thermal performance have greatly improved, andΔTmc is lower, the promotional effect for the crystallizing behavior of rPET is more obvious. Adding nucleating agents, the mechanical and thermal properties of the composite material have a further increase, but the increase of thermal performance is greater than the mechanical properties'. SEM studying found that adding nuclearing agents, the interface between glass fiber and resin matrix becomes better, and glass fibres pulled out by the fracture changed the smooth surface into a significant fixtures.