Preparation And Performance Of Polyacrylate Latex And Blend Latex

The acrylate latex is a kind of widely used latex, which plays a significant role in industrial production and people’s life. However, with the advancement of technology and growth of people’s requirement, the traditional acrylate latex falls into the development bottleneck, and the researches and reports concerning modified acrylate latex appear at this moment. Latex blend as one of modification methods has some unique advantages, such as easy source of materials, low cost, simple technology, moderate reaction and short production period, etc. In the paper, the stable acrylate latex and styrene-acrylate latex were synthesized at first, and then the blend latex having excellent performance was prepared via latex blend by using the two types of latexes above as blend components, at last the blend condition was optimized, on this basis, the performances of latex before and after blending were compared.The thesis consists of three parts:the first part is synthesis of acrylate latex and styrene-acrylate latex, and optimization of emulsifier content. A series of acrylate latexes were successfully prepared via semi-continuous pre-emulsification emulsion polymerization, using ammonium sulfate allyloxy nonylphenoxy poly(ethyleneoxy)(10) ether (DNS-86) and octylphenol polyoxyethylene(10) ether (OP-10) as the emulsifiers respectively, ammonium persulfate as the initiator, methyl methacrylate (MMA) and butyl acrylate (BA) as the main monomers, and acrylic acid (AA) as the functional monomer. Without changing other materials, a series of styrene-acrylate latexes were prepared via the same polymerization progress by using BA and styrene (St) as the main monomers. The influences of emulsifier content on the properties of latex and latex film were studied. The results demonstrated that the optimum dosage of OP-10and DNS-86was1.5%and2.5%, respectively.The second part is the optimization of blend system. A series of acrylate latexes and styrene-acrylate latexes containing optimal emulsifier content were chosen to blend pairwise, and the solid content, surface tension and stabilities of each blend system were compared, the results showed that the blend latex consisting of acrylate latex containing OP-10and styrene-acrylate latex containing DNS-86exhibited the highest solid content, lowest surface tension, and excellent stabilities of latex and latex film. Therefore, the optimal blend system was the blend latex consisting of acrylate latex containing OP-10and styrene-acrylate latex containing DNS-86.The third part is the optimization of blend condition and comparison of performances of latex before and after blending. The influences of OP-10content in acrylate latex, DNS-86content in styrene-acrylate latex, blend ratio, blend technology, blend pH value and blend temperature on the performance of blend latex and blend latex film were investigated. The optimal blend conditions were as follows:the amount of OP-10and DNS-86was1.5%, the blend ratio was50:50, the blend technology was semi-continuous method, the blend pH value was7.5, and the blend temperature was50℃. By comparing the performances of latex before and after blending under the optimum blend conditions, it was found that the stabilities of latex blend were favorable, the surface tensile was lower, the distribution of latex blend particles size was more uniform and the thermal stability was improved after blending.