Study On Modification Of Superabsorbent Resin By Weathered Coal Humic Acid And Its Performance

The use of weathered humic acid to synthesise humic acid superabsorbent resin,not only can improve the water absorption of superabsorbent resin,but also to achieve the rational use of resources.In this paper,humic acid was extracted from Huangling County,Shanxi Province weathered coal by nitric acid oxidation.Studying the effects of synthesis conditions on the water absorption capacity of the humic acid superabsorbent resin were investigated by queous solution polymerization and inverse suspension polymerization,respectively to determine the optimal synthesis conditions.The effects of particle size and absorption time on the water absorption capacity of humic acid superabsorbent resin were investigated.The influence of the structure and properties of the superabsorbent resin with the humic acid and the difference of the superabsorbent resin synthesized by different methods were compared by the structural characterization and performance testing of the humic acid superabsorbent resin.The extraction experimental results show that,the optimum extraction condition of humic acid by nitric acid oxidation: acid coal ratio 3mL/g,oxygen water bath temperature100?,oxygen bath time 60 min,alkali concentration 0.3mol/L,under these conditions,the humic acid extraction rate was 71.99%.The synthesis experimental results show that,the optimum synthesis condition of HA-PAA by aqueous solution polymerization method: HA 0.12 g,neutralization degree50%,MBA 0.0008 g,APS 0.042 g.When the optimum size of HA-PAA is 10-20 mesh,the maximum water absorption rate is 1403 g / g,and the water absorption time is360 min.The optimum synthesis condition of HA-PAA by inverse suspension polymerization method: span-60 0.26 g,HA 0.08 g,neutralization degree 35%,MBA 0.024 g,KPS 0.024 g.When the optimum size of HA-PAA is 60-80 mesh,the maximum water absorption rate is 1468.7 g / g,and the water absorption time is 120 min.The FTIR spectrum analysis results show that the HA-PAA synthesized by the two methods both has obvious carbonyl and C-O characteristic absorption peaks,the carbonyl and C-O absorption peak of the superabsorbent resin was changed with the humic acid,Indicating that HA-PAA is humic acid and acrylic acid polymer.The TG spectrum analysis results show that the thermal stability of HA-PAA synthesized by aqueous solution polymerization at 300? was improved,but decreased after 300?,the thermal stability of HA-PAA was improved by inverse suspension polymerization.SEM spectrum analysis results show that the HA-PAA surface synthesized by aqueous solution polymerization and inverse suspension polymerization was deeper than PAA,and the specific surface area of the superabsorbent resin was increased by humic acid.The performance of HA-PAA test results show that,the salt resistance?temperature resistance? acid and alkali resistance?water retention?repeated liquid absorption performance of HA-PAA is significantly better than PAA,the water absorption of superabsorbent resin is improved with humic acid.Comparing the results of two different synthetic methods show that,The salt resistance and water retention of HA-PAA by aqueous solution polymerization are better than inverse suspension polymerization,but the temperature resistance and repeated liquid absorption performance of HA-PAA by inverse suspension polymerization are better than aqueous solution polymerization,the other water absorption properties of HA-PAA by aqueous solution polymerization and inverse suspension polymerization are basically the same.