Preparation Of Straw-based Polymer Composites And The Water Retention And Sand Fixation Properties

Water shortage is becoming a growing worldwide problem in arid and semi-arid ecosystems.Soil salinization,malnutrition and desertification have become serious environmental and global social and economic problems,these serious problems are facing our country,which affect the normal production and life of our people.Therefore,taking reasonable and effective sand control and sand control measures to restore the fragile ecological environment is important to our country’s sustainable development strategy.The new type of environment-friendly sand-fixing material should not only have the characteristics of strong cohesive force to bond the sand grains together to form a consolidation layer,but also have good water absorption and water retention capabilities to slow down the evaporation of water in the soil and store water.so as to provide sufficient water and a good growth environment for the growth of sand plants.Natural polymer materials are mainly derived from biological raw materials,and have the advantages of wide sources,non-toxic and non-polluting,and polymer water-absorbing materials have good water retention and water absorption properties.Here,two kinds of polymer materials were prepared by grafting polymerization in solution,and applied to the research of water retention and sand fixation.The influence of various factors on the properties and performance of composite materials was discussed.Appearance characterization and application performance testing.The main contents are as follows:1.A low-cost,environmentally friendly superabsorbent composite(SAC1)was prepared by radical polymerization method using wheat straw cellulose(WSC),laterite(LA),acrylic acid(AA)and acrylamide(AM)as the main raw materials.Materials are analyzed and tested,factors which affect material properties are discussed using a single factor experiment and their water retention properties and swelling properties in different salt solutions were tested.The results show that the swelling curve of SAC1 conforms to the pseudo-second-order swelling kinetic model,and has good water absorption properties(790 g/g in distilled water,290 g/g in tap water,95 g/g in 0.9 wt% Na Cl solution)and p H stability(p H = 4-10).Moreover,it has good swelling ability in anionic surfactant solution and good adsorption ability for high-valent metal ions.The effects of soil type,particle size and superabsorbent resin content on soil water evaporation were tested,and SAC1 has a good application prospect in desert areas.2.The superabsorbent composite(AMG-g-P(AA-co-AMPS)/MCC)(SAC2)was prepared by radical polymerization method using ablmoschus manihot gum(AMG),microcrystalline cellulose(MCC),acrylic acid(AA)and 2-acrylamide-2-methyl-1-propanesulfonic acid(AMPS)and applied it to prevent water leakage in deep soil.Among them,MCC extracted from wheat straw was used as the framework to enhance the porous structure of SAC2,and AMG was used as the main body of the water-absorbing material.Due to the uniform distribution of many pore structures inside AMG-g-P(AA-coAMPS)/MCC,and the swelling capacity of SAC in distilled water,tap water and 0.9 wt%Na Cl solution reached 1240 g/g,248 g/g,80 g/g.It also has better swelling properties in different salt solutions and p H solutions,and the application in soil can reduce water loss in soil,as well as can effectively reduce soil water seepage.Therefore,SAC2 have broad application potential in agricultural and desert areas.3.A new type of composite chemical sand-fixing material(WSC-g-P(AA-co-AM)/LA)was prepared by wheat straw cellulose(WSC)and laterite(LA),acrylic acid(AA)and acrylamide(AM)as the composite monomers.The effects of the content of sand-fixing materials on the relevant sand-fixing properties were investigated,and the UV-aging resistance,high-temperature aging,freeze-thaw resistance,water retention and water erosion resistance of the sand-fixing samples were tested.After testing,after adding 2 wt%WSC-g-P(AA-co-AM)/LA sand fixation material,the compressive strength of the sand sample was significantly enhanced,and the sand fixation such as water erosion resistance,thermal aging resistance and freeze-thaw aging resistance better performance.Therefore,the composite sand-fixing material has good sand-fixing potential in desertified areas.