Study On Water-borne Polyurethane Modified By Epoxy Resin And Inorganic Nano-particle

In this paper, water-borne polyurethane modified by epoxy resin was synthesized with polyether diol, dimethylol propionic acid (DMPA), isophorone diisocyanate (IPDI), epoxy resin etc. Effects of the addition method, the content and variety of epoxy resin, NCO/OH ratio, the content of DMPA was studied on viscosity and rheology of emulsion, water-resistance, adhesive strength and tensile strength. The results showed that the chemosynthesis with E-51 was better. With the increase of content of E-51 the viscosity decreased at first and then increased. The rheology of emulsion was invariable. The particle diameter, water-resistance and tensile strength increased, electrolyte stability decreased, but adhesive strength increased at first and then decreased. With the increase of the NCO/OH ratio, the water-resistance and tensile strength were enhanced, the viscosity and adhesive strength increased at first and then decreased. In a given range, the adhesive strength and tensile strength increased at first and then decreased with increasing of the content of DMPA, but the water-resistance was reverse.In the research, The water-borne polyurethane — nano-TiO₂ compound emulsion was also prepared by the reaction of tetrabutyltitanate(TET) with polyether diol, dimethylol propionic acid (DMPA), isophorone diisocyanate (IPDI) according to the principle of sol-gel. It was discussed that effects of contents of TET and ethanol (EA) on the compound emulsion. FT-IR was applied to analyze the PU- TiO₂ emulsion. Particle size analyzer determined the particle size. It was concluded that when the content of TET was less than 5wt% and EA/TET ratio was 5, the stable emulsion was prepared and the particle size was about 100nm. In addition, electrolyte stability and adhesive strength were improved.