Study On Synthesis And Properties Of Self-crosslinking Core-shell Structure Versatate-acrylic Emulsion

With increasing environmental consciousness,developing environmentally friendly paint is becoming the dominant trend.Acrylic resin has become an important coating polymer for its excellent properties in resistance of weather,water,alcohol and stain.Due to the poor properties in film forming and hardness,its application in waterborne coating has been limited.The self-crosslinking core-shell structure versatate-acrylic emulsion and waterborne wood coating were obtained.The product meets the market demand,through analyzing requirements for waterborne coatings.A self-crosslinking versatate-acrylic emulsion with core-shell structure was synthesized by semi-continuous seed emulsion polymerization.The MMA,ST,BA and MAA were chose as comonomer,VV-10,IBOMA and GMA as functional monomer,DAAM and ADH as crosslinking monomer and crosslinking agent.The effect of reaction temperature,stirring speed,pH buffer,emulsion system,initiator and glass temperature(Tg)of core-shell polymer on the emulsion properties were studied.The effect of the content of VV-10(polymer monomer),MAA(acid monomer),GMA(functional monomer)and DAAM-ADH(crosslinking system)on the emulsion film properties and the stability of emulsion were also investigated.The results indicated that the emulsion has good appearance,small particle size,low viscosity and high conversion rate when the process parameters are:(a)using sodium lauryl polyoxyethylene ether sulfate(PCA078)and primary alcohol polyoxyethylene ether(EH-40)as well as the mass ratio 1:3,(b)total content of PCA078 and EH-40 was 2.2 wt% of monomer,(c)polymerization temperature and stirring speed was 80~85 ? and 200 r/min,(d)pH puffer and initiator content was 0.2~0.25% and 0.4~0.6%.The emulsion has a lower minimum film forming temperature when Tg of core and shell was 75~80 ? and 10~20 ?.When the content of VV-10,MAA,GMA and DAAM-ADH was 6%,3%,1~1.5% and 9%,emulsion film has good resistance to water and alcohol.The emulsion film has excellent properties in hardness and sanding.According to the TGA and FTIR,emulsion has an excellent thermal stability and the monomers were all participated in the copolymerization.DSC and TEM show that the synthesized emulsion has two distinct glass transition temperatures and emulsion particles have obvious core-shell structure.The result proved the success of the acrylic emulsion on particle design.The self-crosslinking waterborne primer was obtained by using the synthesized self-crosslinking versatate-acrylic emulsion with core-shell structure as the film forming materials,through choosing the best film forming agent and wetting dispersing agent.The synthesized product,with excellent properties in sanding,compatible,glossiness and low cost,could meet the requirements of the use of wood primer and has good market prospects.