Study Of Polyurethane Resin With Heat Resistance For Vacuum Casting Manufacture

Rapid Prototyping & Manufacture (RP&M) technology was commercialized in the eighties of the twentieth century , It is a new and advanced manufacture technology which is composed of CAD,CAM,CNC,laser,Materials and so on. Low costs,high speed and high efficiency endow it with great value in the intensive competition in the market, so it has attracted great attention in the fields of manufacture industry and academy. Rapid Tooling (RT) is another important technology founded on RP&M, rapid tools or molds can be manufactured rapidly by RT. Materials is one of the most pivotal factors used in RP&M . Polyurethane resin (PU) is an important materials and used widely for Vacuum Casting manufacture because of its convenient process and high performance . But Casting Polyurethane resin (CPU) can not be used as material on the fields of high temperature, so study of CPU with heat resistance , used for Vacuum Casting manufacture, became very significant, and was done the thesis. Series of casting polyurethane resins (CPU) were synthesized by using 4.4'-methylene diphenyl dissocyanate (MDI), cycloaliphatic diisocyanate (H12MDI), polyols, crosslinking agent, catalyst and special aids, and they were prepared by semi-prepolymerization. Their structures were studied by FTIR,and domain structures were studied by WAXD. the thermal stabilities of CPU were examinated by DSC and TGA . The mechanical properties of CPU were measured , the results show that they have high thermal stabilities and excellent mechanical properties. It can be used as material on the fields of high temperature, high impact strength, etc.