| In recent years,we not only demand for more and more superabsorbent polymers materials every year,but also increasing their quality.At present,Superabsorbent polymers are used mainly as absorbents in sanitary.With the development of the western region and the country attached great importance to environmental protection,superabsorbent polymers materials will be widely used in the fight against the desert,to prevent soil erosion, afforestation,and other aspects of wastewater treatment.Therefore,to speed up the superabsorbent polymers materials of our country has a very important significance.In order to find low-cost raw,high-performance,and friendly environment materials,In this paper,Superabsorbent by graft copolymerization of poly(acrylic acid)onto starch was prepared by solution polymerization method,Studied of its water-absorbing,water-holding, adsorption and degradation of performance,its main findings are as follows:1.The influences of reaction conditions,such as initiator content,crosslinker content, neutralization degree,reaction temperature and reaction time on the water-absorbing capacity of tested sodium acrylate was investigated.Based on the experimental results,when the initiator content was 0.35%,the crosslinker content was 0.05%,the neutralization degree was 80%,and reaction temperature was 60℃,the quality of starch and monomer ratio was 1:12.5. Superabsorbent by graft copolymerization of poly(acrylic acid)onto starch was prepared successfully.And its water-absorbing capacity can reach 770 mL/g and 75 mL/g in distilled water and in 0.9 wt%NaCl solution,respectively,compared to poly(acrylic acid)polymer,its water-absorbing capacity increased 65%and 25%.2.We studied the swelling rate of superabsorbent by graft copolymerization of poly(acrylic acid)onto starch with the granularity was 100-200,which have shown that the swelling rate of composites reached the highest of 11g/(g·s),in distilled water at 20℃after 10s,the swelling rate of composites turned into the platform area after 100-120s,and then changed slowly.3.In the range of 20-50℃,the water-holding reaction of superabsorbent by graft copolymerization of poly(acrylic acid)onto starch was tested and studied.The results show that the water-holding reaction of superabsorbent by graft copolymerization of poly(acrylic acid)onto starch was better than polyacrylic acid polymer,in natural conditions.20 and 30℃. however the water-holding reaction of them were the same,in 40 and 50℃;Its water-absorbing process followed after the zero-order reaction,the reaction rate constant k=2.9641×l03 exp(-Ea/RT)with the apparent activation energy Ea=19.3385KJ/mol.4.In the range of 20-40℃,the adsorption behaviors of CuSO4 in superabsorbent by graft copolymerization of poly(acrylic acid)onto starch was tested and studied.The results show that:during 2-3min at room temperature,the water-absorbent resin adsorption of CuSO4 has been closer to a state of equilibrium,and then the adsorption was a slight downward trend;the high-water-absorbent resin has been completely adsorbed when the concentration of CuSO4 was 2g/L;the adsorption behaviors of dilute solution of CuSO4 with high-water-absorbent resin at room temperature was in accordance to Freundlish relationship with an equilibrium absorbing capacity ofΓe=0.06c0.3g/g,the process of high-water-absorbent resin adsorption of CuSO4 was including physical adsorption and desorption.and this adsorptional process followed after the first-order reaction,the reaction rate constant k=6.92×10-9exp(-EaKJ/RT) with the apparent activation energy Ea=-35.4184KJ/mol.The adsorption of CuSO4 with high-water-absorbent resin could perform quickly at lower temperature and was exothermic reaction.5.The degradation process of superabsorbent by graft copolymerization of poly(acrylic acid)onto starch was studied.The Fourier Transition Infrared(FTIR)analysis suggested that the high-water-absorbent resin had a degradation reaction under the ultraviolet ray treatment. It is a new type of friendly environment materials.
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