This study is related to an integrated process for the application of CO2 to poly(hydroxy urethane) and hydrogel via poly(1,3-dioxolane-2-oxo-4-yl)methyl methacrylate [poly (DOMA)]. Quaternary ammonium salts showed good catalytic activity in the synthesis of poly(DOMA) by the direct incorporation of CO2 into poly(glycidyl methacrylate) [poly(GMA)]. Poly[3-(N-butylcarbamoyloxy)-2-hydroxypropyl methacrylate] [poly(CHPMA)] was successfully synthesized from poly(DOMA) and n-butylamine. Hydrogels were also prepared from the poly(CHPMA), using several diisocyanates as crosslinkers, and their swelling degrees were studied by measuring water content in the hydrogels.