| In recent years, with the rapid growth of China’s economy, our country pay close attention to protecting environment. Use polymer emulsion as the main constituents, polymer cement-based waterproof coating(JS) has not only the characteristics of hardness and softness, but also a low-carbon and environmental protection, which has replaced traditional solvent-based waterproof coatings and become the mainstream products on the market. Among the all JS waterproof coating, Acrylic emulsion and styrene-acrylic emulsion has a good over-all performance, however the high cost make the market share is not high; EVA emulsion has high performance-price ratio occupy a large market share, but the film forming temperature is high and bad cold resistance limited its application in winter or in northern. Polyvinyl acetate emulsion has a low cost, safe and convenient to use, widely used in adhesive application in the market at present. However, polyvinyl acetate emulsion’s water resistance and mechanical properties are not very good. In order to produce high performance-price ratio and comprehensive property coating, the paper introduced copolymer and crosslink system in Vinyl acetate-Acrylic emulsion, to obtain the performance requirements of coating waterproof application, and apply modified emulsion to JS.The paper first used vinyl acetate(VAc), butyl acrylate(BA), acrylic acid(AA), used KH-570 as organ silicon crosslinking monomer, used excessive ammonium per sulfate as an initiator. Use the OP-10 and MS-60 as emulsion. Used semi-continuous polymerization method to prepare a silicone modified vinyl acetate-Acrylic emulsion. Meanwhile, paper studied the initiator, emulsifiers, monomer conversion rate, water resistance and other properties on crosslinking emulsion. The paper also studied the sequence structure composition of every stages polymerization reaction products, and the performance of emulsion used in JS. Paper found, when the amount of the organic silicon 2.0 wt.%, a ratio of emulsifier OP-10 / MS-60 = 1?1, amount of emulsifier is 2.0 wt.%, initiator in an amount of 0.5wt.% emulsion has best stability. The water absorption of film decrease to 14.80 %, the elongation at break of JS waterproof coating increase to 201.56 %, the tensile strength also reach to 1.43 MPa; the water impermeability and the low temperature toughness can reach the GB/T 23445-2009 standard. In the end, at the foundation of laboratory experiment, we carried out pilot experiment, and user reflect good after trial the coating.The paper also used semi-continuous polymerization method, made VAc, BA, AA as reactive monomers, used HA as environmental friendly crosslinking monomers, used APS as initiator, Use the reactive emulsifier SN-15 and COPS-1 as emulsion. And added cement, heavy calcium powder and additives to emulsion to prepare JS waterproof coating. When temperature at 80℃, the APS(initiator) amount of 0.5 % the dosage of emulsifier is 2 %, and SN-15?COPS-1 = 1?1, the HA amount of 3 %, the emulsion has good stability; when the hard and soft monomer ratio is 6?4, the HA amount of 3 %, the dispersant amount of 2 %, the defoamers amount of 0.4 %, The water absorption of JS film decrease to 7.16 %, the elongation at break increase to 204.77 %, the tensile strength also reach to 1.86 MPa; the water impermeability and the low temperature toughness can reach the GB/T 23445-2009 standard. Using ultra depth of field microscopy observe the microstructure, the JS film has less defects. |
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