Synthesis And Modification Of Functional Heat-Resistance Polyurethane

Polyurethane was a kind of elastomeric materials between rubber and plastic. It had unique structure, excellent properties. However, its widen application had been limited because of weak mechanical properties and thermal stability. Polyimide was a kind of polymer with great heat resistance, it is an effective way to introduce polyimide into chain segment of polyurethane for performance improvement. Highly branched polymer had novel structure, it could enhance the mechanical properties of polyurethane. Epoxy resin was a great material with high modulus and intensity. It can synthesis excellent properties copolymer with PU as curing agent. Organosilicon materials, with special properties, could give some unusual performance to polymer.In this paper, silane-ierminated poly(urethane-imide)(PUI-Si) was synthesis using2,4-toluylene diisocyanate (TDI), polycarbonatediol (PCDL),4,4’-oxydiphthalic Anhydride (ODPA), KH-550as raw materials. The products showed better thermal stability with introducing imide group and siloxane, the initial thermal degradation temperature of PUI-Si occurred above300℃. The thermal stability was improved obviously.With TDI, PCDL, DMPA and ATA as raw materials, we synthesized highly branched waterborne polyurethane (HBWPU), then HBWPU modified with epoxy resin (HBWPU/EP) by the curing reaction between HBWPU and epoxy resin. The structure was characterized by fourier transform infrared spectroscopy and nuclear magnetic resonance spectrum, showed that the HBWPU/EP was synthesized successfully. The thermal gravimetric analysis and tensile tests indicated the heat resistance and tensile strength of product were enhanced after highly branched structure introduced. The introducing epoxy resin greatly improved the thermal stability and mechanical properties.