Study On Synthesis And Properties Of Alkali-solubility Acrylate Emulsion

In the production of beer packaging, beer labeling required adhesive label on the bottle of beer, and the presence of existing labeling glue tack, poor water resistance, toxic and other shortcomings, especially the most beer bottles are glass bottles, need recycling, which requires cleaning beer bottle label easy to fall off, so the plastic label used for an easily soluble under certain conditions. Alkali-soluble acrylic emulsion adhesive is an initial adhesion, water resistance and is easy to dissolve in alkaline conditions beer labeling adhesives.Based on methyl methacrylate(MMA), butyl acrylate(BA), ethyl acrylate(EA) as the main monomer, acrylic acid(AA) and methacrylic acid(MAA) as functional monomers, potassium persulfate(KPS) sodium bisulfite(NaHSO3) as the initiator and sodium dodecyl sulfate(SDS), alkyl phenol polyoxyethylene ether(OP-10), 80(Tween) as the emulsifier, Preparation of alkali soluble acrylate emulsion adhesives by seed emulsion polymerization and soap-free emulsion polymerization. Get the best synthetic process conditions through discussion and analysis of the factors such as monomer, initiator, emulsifier dosage and ratio, preemulsion time, reaction time, reaction temperature, stirring rate, holding time and so on synthesis process. The resulting polymer was characterized by IR, differential scanning calorimetry analyzer to determine the glass transition temperature, thermogravimetric analyzer to determine the thermal decomposition properties.Seed emulsion polymerization, the research results showed that the prepared polymer is emulsion of milky white with blue light, film casting at room temperature for 24 hours, to get a smooth and moderate hardness of film, alkali-degumming time was 11 min, water absorption was 26.91%, monomer conversion rate was 95.87% and solid content was 47.12% when pre-emulsification time was 30~50min, stirring rate 500r/min, the reaction temperature is 80℃, pre-emulsion dropping time is 3~3.5 hours, mass ratios of soft monomer and hard monomer was 2:1 and mass fraction of MAA was 7% in total monomers, sodium dodecyl sulfate(SDS)/octyl phenol polyoxyethylene ether(OP-10) as anionic/nonionic compound emulsifier and the mass ratio is 1:2,potassium persulfate(KPS) and sodium bisulfite(NaHSO3) as initiators and the mass ratio is 2:1.Soap-free emulsion polymerization, the research results showed that the prepared polymer is emulsion of milky white with blue light, film casting at room temperature for 24 hours, to get a smooth and moderate hardness of film alkali-degumming time was 14 min, water absorption was 12.27%, monomer conversion rate was 88.88% and solid content was 40.63% when mass fraction of AA and MAA were 3% and 6% in total monomers respectively,mass ratios of soft monomer and hard monomer was 2:1, mass fraction of KPS-NaHSO3 was 0.8% in total monomers. After the polymerization heat preservation for a period of time,holding time is 1.5h.FT-IR characterization and analysis of the structure of seed emulsion and emulsifier free emulsion showed that the emulsion is a copolymer of several monomers. The glass transition temperature of the seed emulsion was 25.5℃, and the temperature of thermal decomposition was 243.2℃. The glass transition temperature of the emulsifier free emulsion was 30.2℃, and the temperature was 287.2℃.