一种经济高效的乳液配方方法可提高胶体稳定性并改善成品涂料的性能.pdf

1、A Cost-Effective Approach to FormulateEmulsions Leading to Improved ColloidalStability and Finished CoatingsWhy Improve Coatings1.Growing demand for higher-quality coatings2.Need for increased durability3.Improved adhesion4.More robust and efficient manufacturingprocesses5.Desire for greater transpa

2、rencyOrganic Solventpolymer chain moves freelyapply&drySolventSolvent-borne Coatingborne Coating（Homogeneous SystemHomogeneous System）Sufficient entanglement(good strength)|Easy to cure by various systems|No hydrophilic impuritiessubstratehomogeneous filmany Tg is possibledue to solvent asplasticize

3、rOilWaterStirringSurfactantHydrophobic partHydrophilic partAbsorbs at water/oil interfaceand stabilizes oil droplets inwaterThe Function of a SurfactantThe Function of a SurfactantconcentrationwaterSurfactant MicelleTypical Surfactant only Emulsion PolymerizationTypical Surfactant only Emulsion Poly

4、merizationLipophilicHydrophilicLimited solubility to both water and oil(Styrene,acrylate etc)Localizes at their interface or forms micellepolymer particlein water(2 phases)WaterWater-borne Coatingborne Coating（Heterogeneous SystemHeterogeneous System）polymer chain canonly diffuse over Tghomogeneous

5、filmis formed over Tgabsorbing water,causingblister&whiteninghindering adhesionsurfactant is anuisance at this stage!(no place to stay)colloidal stability isobtained by physicallyadsorbed surfactantsurfactant graduallydesorb(2 1 phase)What is Emulsion PolymerizationMonomer Droplet(1000-10000nm 1012/

6、ml)emulsifierSolubilized monomer(5-10nm 1018/ml)monomermicellegrowingradicaldiffusionpolymer particleswollen with monomermonomermonomerwater soluble radical+trace monomerIngredientsoil-soluble monomer*(*trace amount dissolves in water)surfactantwater-soluble initiator*waterPrimary radicalgeneratesin