Preparation And Study On Single-component Of Polyvinyl Acetate Emulsion

Adhesive is one of the most important part of people's life and industrial production,in recent years, with the improvement of living standards and the development of industry,the original adhesive bonding effect can't satisfy the need of life and industry, There is anurgent need for a higher quality adhesive. The traditional wood glue adhesion agent isgiven priority to with isocyanate monomer, but its operation is complicated, expensivematerials, the toxicity is bigger, and the two-component again, there are a lot ofinconvenience in transportation, packaging, and using. In this paper, based on the presentsituation of the adhesive, from the current social background, to explore the marketdemand and the importance of adhesive, and then to the polyvinyl acetate glue stick to theprevious studies conducted on the basis of improvement and innovation, develop a goodcomprehensive properties of polyvinyl acetate (PVAc) emulsion of vinyl acetate adhesives,expect this high quality adhesive would bring convenience to people's lives, promote theindustrial progress and development.The topic for PVAc emulsion single-component, non-pollution, low cost, etc?Itwill be modified as a starting point, to choose the appropriate modification methods, selectthe suitable polymerization process conditions, by the orthogonal experiment to optimizethe appropriate dosage of raw materials, and through many experiments, so that test toverify the feasibility of PVAc emulsion preparation program. The process of researchmainly includes the following contents:PVAc emulsion glyoxal condensation of polyvinyl alcohol as protectivecolloid,ethylene-vinyl acetate copolymer (EVA) as the seed emulsion, vinyl acetate (VAC)based monomer, acrylic acid (AA), butyl acrylate (BA) and methyl methacrylate (MMA)as co-monomer, by semi-continuous emulsion polymerization method modified seedswhite latex.The results show that: The first discuss the choice of the kind and amount ofprotective colloid, G-PVA representing hydroxyethyl cellulose (HEC), polyvinyl alcohol(PVA) and ?-methacrylamide propyl trimethoxy silane (KH-570) of the emulsion particlesize distribution, viscosity, water absorption, stability and other properties, the influenceof knowable G-PVA is the best choice of PVAc emulsion protective colloid, and W(G-PVA)=6%(all compared to the quality of PVAc emulsion), PVA acetal degree is20%; at thesame time investigated the occurrence of acetalization of PVA environment,PH=2,G-PVA storage stability and degree of PVA acetals have reached the ideal value. Secondpolymerization methods, reaction temperature, stirring rate and feeding mode on theinfluence of emulsion, using semi-continuous seed emulsion polymerization could obtainwith core-shell structure compound emulsion, and the appropriate W(EVA)=8%~12%, the best temperature is75?, the speed of120~140r/min, the most appropriate way tosemi-continuous feeding, PVAc emulsion could be got the most excellent performance.Again study initiator and emulsifier for emulsion viscosity, the influence of solid content,bonding strength, conversion rate and other properties, learned that W(APS)=0.4%, OP-10and SDS optimal ratio of complex2:1, W(complex)=2%. At last, through orthogonal test tooptimize the dosage of AA, BA, MMA, VAC respectively4%,6%~7%,6%,15%, theviscosity of emulsion is5860mpas., bibulous rate is12.6%. After modified PVAcemulsion by this method, the zeta potential is48.4mv, average particle size is160nm.Polymerization method used in this paper an effective, low cost, simple operation, for therealization of large-scale industrial production was provided.