HYPERBRANCHED POLYMER POLYOLS: THEIR PREPARATION, MODIFICATION AND USE IN THE LEATHER INDUSTRY

A series of hyperbranched poly(amine-ester) polyols (HPAEPs) were synthesized by the polycondensation of N,N-diethylol-3-amine-methylpropionate [prepared by the Michael addition reaction of methyl acrylate (MA) with diethanolamine (DEA)] as an AB(2)-type monomer with trimethylol propane (TMP) as the core moiety, proceeding in one-step procedure in the melt with p-toluenesulfonic acid (p-TSA) as catalyst. Then, it was modified by diethyl malonate (DEM) in the presence of catalyst (anhydrous K2CO3) via transesterification to obtain a water-soluble hyperbranched polymer with active methylene (HPAM), which can be used as formaldehyde elimination agent. The obtained polymers were characterized by FTIR and TGA. The application results show that HPAEP can be used as the retanning agent with reinforcing performance (tear strength increased by 23.3% and tensile strength increased by 11.3%) and bleaching effect (whiteness value increase by 19.8%) meanwhile. The removal efficiency of free-formaldehyde in leather could reach 56.25% at 2% dosage of HPAM for capturing 5h.