Study On Polycarbonate Waterborne Polyurethane Elastomer And Its Hybrid Materials

A range of PCWPU emulsion was synthesized by prepolymer method. The main raw materials are polycarbonate diol(PCDL), polytetrahydrofuran ether glycol(PTMG) and isophorone diisocyanate(IPDI). According to the effects of DMPA content on the particle size and the stability of the emulsion, also its impact on the mechanical properties and the water-uptake properties of the film were studied,we determine the most appropriate content of DMPA. Water absorption of PCWPU was reduced effectively with the adding of polyether glycol(PTMG), at the same time,elastic recovery improved. When the content of PTMG is 20%, the fracture strength of the material changed little, but the elastic recovery rate increased by 30% and the water absorption reduced by 29%. We explored the elastic recovery mechanism of polyether-modified PCWPU by infrared dichroism. We used FTIR peak resolution and fitting technique to handle the amino NH and carbonyl of the PCWPU with the different content of hard segment. According the quantitative analysis, we found that the degree of hydrogen of bonding amino and carbonyl groups were affected.Adding TEOS to prepolymer with γ-aminopropyl triethoxysilane(KH550) terminated, we created nano-SiO2 / WPU composite by in-situ synthesis. A bond formed between the nano-SiO2 and polyurethane, and uniformly dispersed therein which confirmed by analysis and testing of FT-IR and SEM. The properties of emulsion and the water absorption, acid resistance, mechanical properties, thermal degradation of the waterborne polyurethane coating were estimated in order to determine the optimum fil ing ratio of nano-SiO2.