Applied Research Of Stearyl Acrylate In Acrylic Emulsion Polymerization

In recent years,waterborne coatings have been widely used in many fields.People on the performance requirements of waterborne coatings are also getting higher and higher.As the most widely used water paint,acrylate has many excellent properties,such as weather resistance,heat resistance,UV resistance,environment alprotection,non-poisonous and tasteless,non-pollution,the simple preparation process,good construction performance.However,it had bad water resistance and low hardness.To overcome these drawbacks,people do some research and attempt to enhance the performance of acrylate coating,such as preparing a high-performance composite emulsion by adding the functional monomer.Butyl acrylate?BA?,methyl methacrylate?MMA?as main monomers,stearyl acrylate?SA?as the functional monomer,the composite emulsion was synthesized by emulsion polymerization process.The effects of reaction temperature,stirring speed,reaction time,initiator,the emulsifier system,amount of the emulsifier,?-cyclodextrin amount,SA amount and other conditions are investigated on the stability of the polymerization process and the properties of emulsion paint film were investigated.As a novel type of low-temperature phase change materials,the microcapsules with the core of solid paraffin and shell of Poly?Acrylate-co-Stearyl acrylate?s were synthesized.The effects of emulsifier amount,SA amount and shell material content were investigated to obtain the optimized microcapsules.The results showed that:?1?The reaction temperature is 75?,the reaction time is 4h.the best type of emulsifier is emulsifier A/FC-4430,the amount of the FC-4430 is 6%,the initiator type is ammonium sulfate?APS?and peroxidation benzoin formyl?BPO?,the stability of the emulsion polymerization system is higher,and the latex film has excellent performance.Particle size analysis showed that : Cyclodextrin as monomer SA solubilization agent can promote SA to participate in emulsion polymerization.Differential Scanning Calorimeters?DSC?analysis confirmed that: With the increase of the amount of the SA,the copolymers begin to crystallize,resulting in the glossiness of emulsion films decreases.While the tensile strength decreases at first and then increases.When the mole fraction of SA is more than 3%,the side-chain were more likely to be crystallized,the crystallinity of copolymers increases.?2?The amount of emulsifier is 5%,the ratio of core to wall is 2:1,the paraffin microcapsules has the excellent performance.Their surface was smooth and dense,and free of any adhesion.DSC measurements gave two endothermic peaks,and the total enthalpy was 104.73 J·g^-1.The microcapsules keep stable up as well as excellent thermal resistance against long-term thermal aging and thermal cycle near 300 times.SA can significantly improve the total phase change latent heat of paraffin microcapsules,a 11.25% increase.