Preparation And Properties Of Biological Glue And Loess Composite For Water-retention And Sand-fixing

Land desertification is the most serious worldwide environmental problems. The dry and little rain of desertification environment has effect our national life serious, and it is the problems which should be solved on demand for continuous development strategy of china to reasonably controlling the desertification. Presently, engineering sand fixation, biological sand fixation, and chemical sand fixation are common applications in the world. The chemical sand fixation has been a large utilized recently, which could be operated automatically with fast and simple manipulation and take effect rapidly. Especially, it can be utilized in harsh environment and in which engineering and biological sand fixation can not be operated. Superabsorbent material can absorb hundreds or even thousands times water about its own weight, with a strong resistance for acid-alkali and high temperature performance, especially for hot dry desert environment.In this paper, two organic-inorganic composite materials were prepared using guar gum, xanthan gum and loess that widely distributed and abundant store in natural were used as main raw materials, complex with environment-friendly polymer, and the performance used as superabsorbent and sand-fixing agent were investigated. The main work is as follows:1. Novel guar gum-g-poly(acrylic acid)/loess(GG-g-PAA/loess) superabsorbent composites were prepared by graft polymerization in aqueous solution using guar gum(GG), acrylic acid(AA), loess as raw materials, ammonium persulfate(APS) as initiator and N,N-methylenebisacrylamide(MBA) as crosslinker. The structure of superabsorbent composites was characterized by FTIR and SEM. Effects of loess content on swelling capabilities and swelling kinetics of superabsorbent composites was studied. Water-retention properties at various temperatures, reswelling capabilities and water absorbency at various pH solutions of superabsorbent composites were also investigated. The results indicated that GG and loess participated in graft polymerization reaction with AA. The introduced loess can remarkably enhance the capability of water absorption and the superabsorbent composite containing 2% loess had the best absorption of 602 g/g. The water retention for the superabsorbent composite is still more than 28% after 6 d, at room temperature and after reswelling 5 times, water absorbency can maintain 49% of the initial time. In addition, the superabsorbent composites showed excellent pH-stability.2. A new, low-cost, and eco-friendly organic-inorganic composite superabsorbent was successfully synthesized in aqueous solution by polymerization xanthan gum(XG), neutralized acrylic acid(AA) and loess using ammonium persulfate(APS) as initiator and N,N-methylenebisacrylamide(MBA) as crosslinker. Structure and morphological characterizations of the composite superabsorbent were investigated by Fourier-transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). The loess content, pH values, surfactants, salts and temperature which could affect the swelling and water-retention capabilities of the composite superabsorbent were investigated. The composite superabsorbent exhibits excellent water absorbency(610 g/g in distilled water), pH-stability(pH 5-10), and higher swelling capacity in anionic surfactant solution, on the other hand, the composite superabsorbent can be used for removing multivalent metal ions.3. A novel guar gum/poly(acrylic acid)/loess(GG-g-PAA/loess) organic-inorganic composite used as chemical sand-?xing agent(CSFA) is successfully prepared in aqueous solution by polymerization guar gum(GG), neutralized acrylic acid(AA) and loess. The correlations between the content of prepared composite and the sand-?xing properties are investigated. The results show that the CSFA can signi?cantly improve the compressive strength of the sand fixation specimens. Meanwhile, the sand fixation specimens has good thermal, freeze-thaw and UV-radiation aging stabilities to withstand the changes in temperature and strong UV radiation. Besides, the specimens treated with sand-fixing agent shows excellent water retention capacity.