[Objective] The paper aims to discuss urea's accumulative releasing ratios of polyacrylates with different types of side groups or different contents. [Method] Polyacrylates with different side groups are synthesized and made into membranes with the same thickness. The water contact angles and urea release curves of different polymers are obtained in the same conditions. [Result] The adding of hydroxyethyl acrylate or acrylic acid would diminish the water contact angles and improve the hydrophily,and with m...