Modification Of Epoxy Acrylate Latex With Functional Monomers And Silane Coupling Agent

Composite materials have been one of research hot spots.Epoxy acrylate has aroused extensive attention because of its good integrated performances such as outstanding adhesive properties,heat resistance,flexibility,and chemical resistance.In order to obtain the latex with better overall performances to meet the application requirements,it is very necessary to do some researches focusing on modification of epoxy acrylate latex.In this thesis,a series of stable epoxy acrylate latexes with preferable properties were prepared via a facile emulsion polymerization process,with ammonium persulfate(APS)as initiator,butyl acrylate(BA)and methyl methacrylate(MMA)as main monomers,sodium dodecyl sulfate(SDS)and octylphenol polyoxyethylene(10)ether(OP-10)as emulsifiers.The epoxy resin E-51 was dissolved in acrylate monomers to pre-emulsified and then added to reaction system.The effects of reaction conditions and reaction mechanism and the amount of E-51 as well as the modification of functional monomers methacrylic acid(MAA)and 2-ethylhexyl methacrylate(EHMA)and silane coupling agent y-methacryloxypropyltrimethoxysilane(KH-570)on the performance of epoxy acrylate latexes and films were discussed.This thesis consists of four parts.Part One,the discussion and investigation of the polymerization reaction conditions and reaction mechanism.After determining the reaction temperature 82 ± 2 ?,the improved facile emulsion polymerization has showed that it can significantly improve the stability of the emulsion compared with the traditional one.Furthermore,when the ratio of seed monomer and monomer in pre emulsion is 3:7 the latex has good integrated performance.Then the reaction mechanism was figured out,what happened in the polymerization reaction was that the unsaturated monomers grafted onto the aliphatic carbon chain of the epoxy resin.Part Two,the influence of E-51 amount on the performance of epoxy acrylate latexes.The results showed that the solid content and conversion firstly increased then decreased after adding E-51,and the latex can keep good stability.The latex particles increased with the increasing of the amount of E-51.The viscosity and surface tension of the latex decreased slightly compared with the blank sample.With increasing amount of E-51,the toughness,resistances to water,acid,alkali and alcohol,heat resistance and adhesion force of latex films all improved while the tensile strength decreased.Comprehensive comparison showed that the latexes prepared with 20%of E-51 had good performance.Part Three,the influence of MAA and EHMA on the performance of epoxy acrylate latexes.The results showed that the introduction of MAA or EHMA could keep latexes with high conversion and gloss.The latex particle size first decreased and then increased with the increasing of the amount of MAA or EHMA.The introduction of MAA can promote polymerization reaction rate to a certain extent,and also improve the tensile strength and adhesion force.The heat resistance of the samples with MAA was significantly better than EHMA.Comprehensive comparison showed that latexes prepared using 2%of MAA had good performance.Part Four,the effect of silane coupling agent KH-570 on the performance of epoxy acrylate latexes.The results showed that the comprehensive performance of the latex was good when the dosage of KH-570 was 0.6%.After adding KH-570,the solid content and conversion of latex had a slight decrease but the latex still kept good stability.The fracture mode of latex films remained ductile after introducing KH-570.And the incorporation of KH-570 could improve the resistances to acid,alkali and alcohol and keep latexes with good adhesion force,flexibility and impact strength.Also the gloss was enhanced when the amount of KH-570 was small.Moreover,the tensile strength and thermal stability of latex films all improved,and the tensile strength increased with the increasing of the amount of KH-570.