The Preparations And Properties Of Hydrogels With Bi-functional Group(OH And COOH)

The hydrogel with bi-functional group (OH and COOH) were prepared with different monomers and different methods, the structure analyses and swelling capacity under different reaction conditions and surroundings were investigated. The results showed: (1) In the suspension polymerization of methacrylate and vinyl acetate, when reaction temperature was 58-60, MA/(MA+VAc) was 60%, the conversion was higher. When number of AIBN was 0.1%-0.2%(wt), MA/(MA+VAc) was 50%-60%, the water swelling capacity of hydrolyzed product was higher; when the value of COOH/(COOH+COO'+OH) was adjusted to 40%-50%, the water swelling capacity and strength of the product were higher than others. (2) In the solution copolymerization of methacrylate and vinyl acetate under microwave irradiation, when microwave power was 360W, irradiation time 152min, number of BPO 0.25wt%, number of MBAA 0.5wt%, MA/(MA+VAc) 70%, and solvent/ monomer l(wt), a higher conversion should be reached. When irradiation time was 92min, number of BPO 0.15%-0.20%(wt), number of MBAA 0.2wt%, and MA/(MA+VAc) 50%, a higher swelling capacity were to be reached. Compared with heating polymerization, at the same reaction conditions, the conversions of polymerization were higher, but the water swelling capacity of hydrolyzed products were lower. (3) In the solution copolymerization of vinyl acetate and maleic anhydride, when VAc/(M+VAc) was 45%-55% (wt), number of BPO 60%-70% (wt), and monomer/(solvent+monomer) 1/1.75, a relative higher conversion should to be reached. When number of MBAA was 0.6wt%, VAc/(M+VAc) 80%-85%, number of BPO 0.55wt%, and hydrolyzation with 0.28-0.56g NaOH per 1.84g copolymer, a relatively higher swelling capacity could be reached; and when acid was added to hydrogel, the swelling capacity should be lower but strength higher.