Synthesis Of Acrylic Acid Polymers And Their Performance On Sand Solidification

In this paper, polyacrylic acid was synthesize by photoinitiated polymerization, which can be used as sand fixing agent. The compressive strength, shear strength and wind erosion resistance of solidified sands was studied. Experimental results show that the compressive strength of solidified sands is more than 1MPa, which can resistance wind erosion effectively. Through SEM characterize of the cross-section morphology, we can realize the fundamental of sand fixing agent.We propose a new method of sand fixing according to the characteristics of water evaporation in the desert. The copolymers of 1H, 1H,2H,2H-Perfluorooctyl methacrylate (PFOMA) and acrylic acid (AA) with different monomer ratios, AA/PFOMA=9/1,8/2,7/3 and 5/5, were synthesized by AIBN initiated free radical polymerization. The specimens of the PAA solidified sand were soaked in the aqueous dispersions of the fluorocopolymers to coat a hydrophobic layer. The static water contact angle measurements demonstrated that the copolymer layer can significantly reduce the surface energy of the specimens, from about 0° without the copolymer coating layer to about 108°. For the PAA solidified specimen with 5 cm height, it took about 23 '33" for 25 ml water flowing it. With the copolymer of AA/PFOMA=7/3 as coating layer, the water can not penetrate the specimen. With the copolymers of AA/PFOMA=9/1 and 8/2, the water flow time drastically reduced to about 4'30 ". It also found that with the coating of the copolymer the water absorption of specimen dropped from about 50% of PAA solidified sand to about 15% of coated specimens.Through CaCl2 solution infiltrate the PAA solidified sands compare with the PAA solidified sands in the water for one month. The surface of PAA solidified sands which after infiltrate is stiff, but the sand of PAA solidified sands was dropped which did not infiltrate by CaCl2 solution. The results show that the water resistance of the PAA solidified sand is greatly improved by the addition of the CaCl2 solution which resulted the crosslink of the PAA.