| Many researches had been made on salt - resistant superabsorbent in our previous studies. To ulteriorly improve the water absorbency, the absorption rate of xerogels in physiological and the properties of swollen hydrogel such as strength, resilience, dispersion, dry and crispy on the hydrogel surface, a series of copolymerized superabsorbents based on the monomers of acrylic acid, acrylamide, 2 -hydroxypropyl acrylate et. al or their derivations were prepared, respectively. And several important results were gained as follows:(1) Salt - resistant superabsorbent was synthesized based on acrylic acid and acrylamide after being surface - crosslinked by ethylene glycol diglycidyl ether (EGDE) and modified by inorganic salt. The effect of various experimental conditions, such as reaction temperature, reaction time, neutralization degree of acrylic acid, amount of acrylamide, initiator, and crosslinking agent were investigated. Then the orthogonal design was employed to study the mutual effect of each reactive factor on swelling properties, and the superabsorbent with excellent strength, resilience, dispersion, dry and crispy on the hydrogel surface was prepared. The product prepared under the optimal conditions possessed the water absorbency of 60 g/g in 0.9 wt% NaCl aquous solution at atmosphere pressure, which was almost equal to that of the product of Sanyo Co. (Japan), and the water absorbency of 18 g/g under load, which was 1.7 times of the product of Sanyo Co.(2) The copolymers prepared by sodium acrylate and 1 - (acryloyloxy) propan - 2 - yl phosphate were surface - crosslinked by EGDE and blended with inorganic salt. Based on the comprehensive investigation of every reactive factor, the orthogonal design was employed. The water absorbency of the resulting product under the best condition in 0.9 wt% NaCl aquous solution at atmosphere pressure and under load was 65 g/g and 17 g/g, respectively. Moreover, excellent strength, resilience, dispersion, dry and crispy on the hydrogel surface could be shown by this sample.(3) Fast - swelling porous superabsorbent resin was synthesized through a solution polymerization of partially neutralized acrylic acid and acrylamide by adding poly (ethylene glycol) and some porosity generators. Firstly, we selected the optimum porosity generator, polymers for interpenetrating, crosslinking agent, and surfactants; then we investigated the influence of some important reactive factor, such as reaction time, neutralization degree of acrylic acid, amount of initiator, crosslinking agent, and poly (ethylene glycol), on the absorption properties. The water absorbency of best product in 0.9 wt% NaCl aquous solution at atmosphere pressure and under load were 61 g/g and 16.7 g/g, respectively, and the absorption rate was 22.003×10-3 g/(s.g). Furthermore, the excellent properties of swollen hydrogel, such as strength, resilience, dispersion, dry and crispy on the hydrogel surface, were obtained.(4) Combining the viewpoint of thermodynamics with the basic knowledge of physical chemistry, we proposed a new method, the conductance method, for tracking the swelling kinetics of superabsorbent. Based on this method, the swelling kinetics mechanism of superabsorbent was further developed.(5) Thinking of the effect of types of the superabsorbent and the swelling medium on the capacity of the absorbent, the swelling kinetics of three types of salt - resistant superabsorbent in various saline solutions were investigated and compared. The results showed that the swelling ratio and the swelling behaviors of different resins changed a lot with the swelling medium. Moreover, the results were logically explained.
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