Syntheses Of Waterborne Polyurethane/ Polyacrylate Hybrid Emulsions Based On Poly (Butylene Itaconate) Ester

Waterborne polyurethane(WPU) is a type of polyurethane system with water as dispersion medium. Due to its excellent properties, it is widely used in the fields of paper-making, paint, leather, adhesive industries and so on.In this paper, waterborne polyurethane based on poly(butylene itaconate) ester(IWPU) with poly(butylene itaconate) ester(PBI) which was bio-based polyester was prepared. The emulsions and films were characterized by fourier transform infrared(FTIR) spectra, thermogravimetric analysis(TGA), differential scanning calorimetry(DSC) and transmission electron microscopy(TEM). The results indicated that, emulsions with better performances can be obtained under the conditions: the number average molecular weight of PBI was 1109-2589 g/mol, PBI content was 35 %-60 %, R was 1.1-1.33, DMPA content was 5 %-6 %, adopting after-neutralization technology with triethylamine(TEA) as neutralizer and the neutralization degree was 100 %. Thermal property of IWPU film was good and glass transition temperature was 10 °C.In order to improved the heat resistance and water resistance of IWPU films, crosslinked IWPU emulsions and silicone modified IWPU emulsions were synthesized with trimethylolpropane(TMP) as the crosslinker and poly(methyl(trifluoropropyl) siloxane)(PMTFPS), respectively. The films were characterized by TGA and DSC. The results showed that, the preferential dosage of TMP was in the range of 0.3 %-1.5 %. For the cast films of crosslinked IWPU, the water absorption was reduced by 7.31 %, the temperature of 10 % weight loss increased by 34 °C than IWPU, and glass transition temperature increased by 11 °C. Particle size of silicone modified IWPU emulsions increased than IWPU, and the stability decreased. For the cast films of silicone modified IWPU, water absorption was reduced by 17.57 %, the temperature of 10 % weight loss decreased by 24 °C, and glass transition temperature decreased by 9.8 °C.Polyacrylate modified IWPU were synthesized with methyl methacrylate and butyl acrylate by emulsion polymerization. The structure and properties of emulsions and films were characterized by FTIR, TGA, DSC and TEM. The results showed that, emulsions with better better performances can be obtained under the conditions: mass content of azodiisobutyronitrile(AIBN) was 0.75 %, reaction temperature was 70 °C,the time of feeding was 3 h, HEA content was 50 %-100 %, and IWPU content was 30 %. For the cast films of IPUA, the water absorption was reduced by 13.89 % than IWPU, the temperature of 10 % weight loss increased by 49 °C, as well as glass transition temperature reduced by 21.6 °C. The application test shown that screen clogging and pilling resistance of polyacrylate(PA) printing binder were improved due to IWPU.