Preparation And Characterization Of Water Micro-expansion Swellable Rubbers

With the development of technology, materials with properties to meet newdemands are needed. Water swellable rubber (abbreviated as WSR) appeared in thelate1980s, and successfully applied to the construction of large civil engineering, oilproduction, water conservancy, moistureproof packaging etc. This thesis designed andsynthesized the polyacrylate rubber with epoxy functional groups, and the rubber wasmodified with a series of hydrophilic or water swellable materials, such as polyacrylicacid-Kaolin. Basic properties of the as-prepared composite rubber were characterized.The modified rubber with property of limited expansion upon water absorption, mayfind applications as sealing materials used in harsh environment with water, salt,hydrogen sulfide, oil and high temperature.The main contents of this paper are as follows:First of all, on the basis of understanding the basic properties of various kinds ofrubber, the polyacrylate rubber with epoxy functional groups was chosen as the rubbermatrix. Using ethyl acrylate and glycidyl methacrylate as monomer, acrylate rubbercontaining epoxy groups were synthesized by emulsion polymerization method. Themain influence factors on the synthesis of acrylate rubber (the choice of emulsifier,the stability of pre emulsion etc.) were investigated. The products were characterizedby FTIR and TG, etc.Second, a series of water absorbent resins (PAA-Kaolin)with different kaolincontent were synthesized and were characterized by FTIR, TG and XRD. Waterabsorptionand and water absorption rate of the resins were measured.The third, hydrophilic polymers PVA and PAA-kaolin were blended with theepoxy group-containing polyacrylate rubbers, respectively, to obtain water swellablerubbers. The as-prepared composite rubbers were characterized by SEM and TG, andphysical properties were measured before and after absorbance of water.. It was foundthat the PVA-modified rubber turned to be hard and brittle, while the addition ofPAA-kaolin gave composite rubbers better comprehensive properties such as tensilestrength, elongation at break and other physical properties.