Synthesis And Properties Of Epoxy Acrylate Soap-free Emulsion With Core-shell Structure

The polymerization of Soap-free emulsion with core-shell structure is a new polymerization technology combining soap-free emulsion polymerization and core/shell emulsion polymerization,which combines the advantages of both.This topic starts from the concept of safety environmental protection.Emulsion polymerization monomer is used as the dispersion medium of epoxy resin to prepare epoxy acrylate.It can increase the grafting rate of epoxy resin and acrylic acid,while avoiding the residue of organic solvent volatilization and environmental issues.Epoxy acrylate soap-free emulsions with core-shell structure were synthesized by semi-continuous seed emulsion polymerization.And the properties of emulsions and their application in anti-corrosion coatings were studied.(1)First,the compatibility of epoxy resin E-44 with styrene(St),methyl methacrylate(MMA),and butyl acrylate(BA)as the dispersion medium was studied to determine the optimal compatibility ratio.Then,epoxy resin E-44 and acrylic acid(AA)diluted with polymerized monomers were used as raw materials,triethylamine was used as a catalyst,and hydroquinone was used as a polymerization inhibitor to prepare epoxy acrylate(EA)and its Influencing factors were examined.The experimental results showes that: m(E-44): m(St)=1:1.5,the temperature is 100?,the amount of catalyst is 2%,the amount of inhibitor is 1%,the molar ratio of E-44 to AA is 1:1.05,the polymerization inhibitor dosage is 0.5%,and the esterification rate of epoxy acrylate prepared by reaction 2h can reach 95.48%.m(E-44):m(MMA)=1:1,the temperature is 100°C,the amount of the catalyst is 2%,the molar ratio of E-44 to AA is 1:1.05,the polymerization inhibitor dosage is 0.5%,and the esterification rate of epoxy acrylate prepared by reaction 2h can reach 83.76%.m(E-44):m(BA)=1:1,the temperature is 100°C,the amount of the catalyst is 2%,the molar ratio of E-44 to AA is 1:1.05,the polymerization inhibitor dosage is 0.5%,and the esterification rate of epoxy acrylate prepared by reaction 2.5h can reach 91.22%.The optimum reaction condition which is styrene as E-44 dispersion medium to prepare epoxy acrylate was determined by the comparison of reaction conditions and reaction products.The products were purified and characterized by infrared spectroscopy(FT-IR)and 13 C NMR spectra.The product is in agreement with target product.(2)By semi-continuous seeded emulsion polymerization method,using allyloxy nonylphenoxy alcohol polyoxyethylene ether ammonium sulfate(SE-10N)as a reactive emulsifier,AA as a functional monomer,BA as a shell monomer,the target product prepared in(1)as a core monomer,an oxidation-reduction initiation system was selected to synthesize an epoxy acrylate soap-free emulsion with core-shell structure.The effects of emulsifier dosage,initiator dosage,functional monomer dosage,shell emulsion dropping time,core-shell ratio,polymerization temperature and water dosage on the properties of the emulsion were investigated.The experimental results showes that the synthesized emulsion has better performance when the amount of SE-10 N is 10%,the amount of initiator is 1%,the amount of functional monomer is 1%,the ratio of core to shell is 1:1,the time of shell emulsion dripping is 1.5h,the polymerization temperature is 70°C,the amount of water used was 1.7 times.The solid content of emulsion is 33.40%,and the monomer conversion rate is 96.40%.The chemical structure of epoxy acrylate soap-free emulsion with core-shell structure was characterized by Fourier transform infrared spectroscopy(FT-IR).The core-shell structure of the latex particles was observed by TEM.The results showed that the polymerization reaction is complete,and the TEM results showes that the synthesized emulsion has a distinct core-shell structure.(3)The synthetic emulsion was used as the film-forming material.The formulation of the waterborne anti-corrosion coating determined by the orthogonal test method which was the defoamer dosage is 0.2%,the dispersant dosage is 0.5%,and the pigment-to-base ratio is 1:1.5.The test result of the mechanical properties of the water-based anti-corrosion coating prepared by the best formula.The results showes that impact resistance is not less than 50kg·cm,adhesion grade is 1,extends of flexibility is 1mm.The salt resistance,water resistance and acid alkali resistance of the coating were tested.The anticorrosion performance of the water-borne coatingsprepared by formula 9 is the best.