Synthesis and properties of novel water‐dispersible polyisocyanates

A series of novel water‐dispersible polyisocyanates (WDPs) were synthesized with hexamethylene diisocyanate isoxyanurates (HDI trimer), dimethylol butanoic acid (DMBA), polyethylene glycol monomethyl ether (MPEG‐600) and 1,4‐cyclohexanedimethanol (CHDM) as materials. Two‐component waterborne polyurethane (2K‐WPU) films based on WDPs were prepared and characterized by ultraviolet‐visible spectrophotometer, thermogravimetric analyzer (TGA), scanning electron microscopy (SEM), and surface contact angle measurement. The effects of molar ratios of DMBA/MPEG and CHDM/MPEG and their amounts on properties of WDPs including the water dispersibility, storage stability, films hardness, and water resistance were also investigated. The results showed that the introduction of CHDM could efficiently improve the storage stability, the hardness and water resistance of 2K‐WPU films due to the rigid cyclic structure and hydrophobicity property of CHDM. It was found that WDPs had excellent storage stability, and the 2K‐WPU displayed short tack‐free times, high hardness, good water resistance, excellent surface appearance and gloss with 3:7:3 of the molar ratio of DMBA/MPEG/CHDM. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44735.