| This paper is about preparing anti-salt Superabsorbent polymer, which mainly based on the previous researches, refered to the product features of Sumitomo, and combined with the domestic and foreign researche direction in recent years. It researched the influence of various factors on water absorbency on the basis of the new technology,spray polymerization. Finally, it studied adsorption law of heavy metals by composite absorbent resin through preparing composite absorbent resin with inorganic filling and modification. Details as follows:(1) With acrylic acid(AA) and acrylamide(AM) as monomers, N, N’- methylene bisacrylamide(NMBA) as crosslinking agent, and potassium sulfate(KPS) as initiator, It designed and used the way of spray polymerization to preparing superabsorbent resin microspheres, mean to explore the relationship between structure and performence of Superabsorbent Resin molecule, analysis and studied the effect of monomer ratio, acrylic acid neutralization degree, the dosage of triggered agent, the dosage of cross-linking agent, reaction temperature and ammonia content put on water absorbency rate of resin, and it used orthogonal test(L2556) to optimized polymerization process. The results showed that the water absorbency rate of SAP was highest when the AA neutralization degree is 60%, AM:AA is 1:4, the dosage of crosslinking agent is 0.025%, the dosage of causing agent is 0.3%, the temperature is 100 ℃, and ammonia content is 20 m L. It was espectively 1090g/g and 83g/g in deionized water and 0.9% Na Cl solution.(2) Preparing the superabsorbent resin microspheres with the best reaction condition by spray polymerization, to determinate and analyze the water absorption property, keep water performance, absorption rate, repeated absorption performance and the law of absorbent performance in different cations and anions with different valence states of SAP. The results showed that the anion has less influence on the absorption performance, the rate in different valence cations is Na+>Ca2+>Fe3+ and finally determinated residual monomer of samples by HPLC, which met the national standards.(3) By the method of spray polymerization, using diatomite, acrylic acid, acrylamide and chitosan as monomers, N,N’-methylene bisacrylamide(NMBA) as crosslinking agent, and potassium sulfate(KPS) as initiator, preparing CTS-g-P(AA-AM) /DE composite superabsorbent polymer, studying the effect of diatomite and chitosan amount on water absorbency, exploring adsorption law of chromium and lead by composite absorbent resin contrasted to P(AA-AM). The results showed that the water absorption and retention performance were improved, and the adsorption performance on Cr3+ and Pb2+ raised from 142mg/g and 173mg/g to214mg/g 325mg/g. The descriptinn of adsorption process is more appropriate with secondary kinetic. It used Langmuir and Freundlich equation respectively to polyfit the Adsorption thermodynamics, which showed that the adsorption isotherm was more suitable for Langmuir equation and R2 were 0.994 and 0.998 respectively.(4) Through Fourier transform spectroscopy(FTIR), Scanning electron microscope energy spectrometer(SEM), inductively coupled plasma emission spectrometer(ICP), thermogravimetric analysis(TG-DTA), X-ray diffraction(XRD), it studied the structure, morphology, adsorption properties, thermal stability and crystallization of the superabsorbent resin. The FTIR results showed that acrylic acid and acrylamide has occurred copolymerization reaction and turned to superabsorbent resin.The SEM results showed that the surface of the samples is smooth spherical structure with higher thermal stability. Through XRD and ICP, it showed that the absorbent resin destroyed the original lattice structure of diatomite to form new composite superabsorbent resin whose adsorption capacity increased about 45% compared with unmodified absorbent resin. |
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