Influence of hydrophilic group content on the water resistance of waterborne polyurethane

Anion waterborne polyurethane polymers(WPU) were synthesized by step polymerization using polybutylene adipate glycol(PBA2000),polytetramethlene glycol(PTMEG2000),polyoxypropylene glycol(N220) and isophorone diisocyanate(IPDI) as raw material,using 2,2-dimethylol propionic acid(DMPA) as hydrophilic group.The effect of DMPA on the hydrolysis properties of different polyols-prepared WPUs was investigated by following the change of molecular weight,mechanical properties,and water absorption rate of WPUs to analyze the effect of DMPA on the hydrolysis properties of different polyols-prepared WPUs.The results showed that polyester type polyurethane water resistance is the worst,when DMPA from 4% to 6%.Polyester type polyurethane water resistance is better,in the destruction of 12 d,the largest decrease in molecular weight is about 22%,mechanical properties of 75%,water adsorption maximum 8.01%,PTMEG 2000 synthetic product water resistance is best.