| Currently, paper-plastic adhesive generally has technical difficult problems, such as the inferior adhesive strength. The high solid content emulsion could be obtained by semi-continuous seed emulsion polymerization, with the organic siloxane monomer modified acrylate and vinyl acetate which had good wetting. The performance of polymers was characterized to ensure the molecular structure and a set of ideal conditions were obtained. The relationship of surface properties and peel strength of silicone-modified polymer was tested and studied.The emulsion stability was affected largely by the type and amount of emulsifier. It is showed that the viscosity and stability of emulsion are improved, when the amount of emulsifier composed of anionic and nonionic emulsifier increased. But the amount too more or too less will reduce the bond strength. When the emulsifier in the composite ratio of 1:2 and the amount of monomer was 6%, the emulsion was stable. Using potassium persulfate as initiator, when the initiator dosage was 0.8% of the monomer, the gel ratio of polymerization was the lowest. And when the initiator dosage was 0.6% for the monomer, the monomer conversion was the highest. In the free radical polymerization, the reaction time was longer, the conversion of monomer was higher. However, when reaction time was longer than 2h, the influence of monomer conversion has been modest. Therefore, it is more appropriate that temperature of polymerization is around 85℃and the reaction time is 2h. The different proportion of soft and hard monomers lead to different glass transition temperature of polymers, and the adhesive properties of emulsion are very different. With the increase of the proportion of hard and soft monomers, the peel strength of emulsion on the paper and biaxial oriented polypropylene (BOPP) substrate increased firstly and then decreased. When the proportion is 2.0:1.0, it reached the maximum value.The siloxane modified vinyl acetate/acrylic emulsion was prepared by Pre-semi-continuous emulsion polymerization, which has good adhesion properties on low surface energy materials (polypropylene film). The structure of its shell could be seen clearly in TEM photos, and the diameter of most of the latex particles is about 180 nm. It could increase the concentration of emulsifier molecules in aqueous, avoid the phenomenon of blistering due to Lower polymerization rate in early polymerization, ensure the normal initial response, promote a blue appearance in reaction system, improve the polymerization stability of the phase of monomer dropping to pre-emulsify some of the VAC monomer and initiator and all the emulsifier. As the temperature increased, conversion and gel ratio improved. Controlling the addition of siloxane in a range of 10-30%, the Adhesive properties of the emulsion film can make a larger increase. When the content of siloxane was 20%, the peel strength was 10N/2.5cm.The surface free energy of emulsion film decreased with the increasing content of organic silicon. When the content of silicone copolymers is 10%, the surface free energy decreased significantly. As the organic silicon content increased, the surface free energy showed a slow decreasing trend. When the content of polysiloxane reached 50%, the surface free energy of the copolymer membrane was close to the silicone polymers', which were 20.8mN/m. Silicone copolymer emulsion was part of the invasion on BOPP film. And with increasing silicone content, the extent of infiltration has been strengthened, which is decreased and then increased with the increasing of organic silicon content. It is showed that the addition of silicone copolymer emulsion made the infiltration improve on the BOPP films. And with the increasing amount of silicone added, the invasive of emulsion on BOPP film had a increasing trend, which trend with silicone added more than 30% was slower.
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