Synthesis And Properties Of Fluorined Epoxy Resins

Fluorined epoxy resin possesses good properties which normal epoxy resin has, meanwhile fluorine has strong electronegativity and C-F has short bond which could shield the main chain, these factors would improve the surface property, hydrophobic and oleophobic properties, dielectric property and corrosion resistance of epoxy resin and make it be used as coating, composite material, electronic packaging material and so on. In this thesis, multi-amino fluorinated compound was synthesized by Michael addition between diethylenetriamine (DETA) and dodecafluoro-heptyl methacrylate (DFMA), then added it to epoxy resin to prepared fluorined epoxy resin. This method can not only avoid the bad compatibility caused by physical blending, but also own fine properties which monomer polymerization could achieve. Besides, we can change the fluorine content to obtain products with preferable properties, the process route is simple relatively. The main content includes three aspects below. In the first part, the multi-amino fluorinated compound,1-diethylenetriamimo-2-methyl-dodecafluoro-heptylpropionate, was synthesi-zed. To get the best reaction conditions, reaction temperature, time and ratio were changed. Besides, the effect of aftertreatment on productivity was discussed. The product was characterized by FTIR and1H NMR. The results indicated that the multi-amino fluorinated compound was synthesized successfully, at35℃and reacted for12h, when the ratio was1:1, the productivity was82%. After reaction, the solvent was removed by reduced pressure distillation.In the second part, the epoxy resins with fluorine content of0%,1%,3%,5%,7%were prepared and cured with diaminodiphenylmethane (DDM). The properties of fluorined epoxy resin were investigated by immersion method, static water contact angle test, XPS, mechanical properties test and DMTA. The results indicated that the fluorinated epoxy resin with fluorine content within5%had better medium resistance and bigger water contact angles,113.7°,the hydrophobic properties were improved, the tensile strength and bending strength increased, reached to73.82MPa and114.26MPa respectively, but the impact strength and Tg decreased. The epoxy resin with3%fluorine content had better combination properties.In the third part, to compare the property improvement of fluorined epoxy resin cured by different curing agent, according to the results of second part, the epoxy resins with3%fluorine content were prepared and cured by DETA and DDM respectively. As comparison, the corresponding epoxy resins with0%fluorine content were prepared. The effect of fluorine content on medium resistance, surface properties, mechanical properties and heat resistance of fluorinated epoxy resin were investigated. The results indicated that relative to epoxy resin with0%fluorine content, epoxy resins with3%fluorine content cured by the two curing agents had better medium resistance and hydrophobic properties, the tensile strength and bending strength increased and the impact strength decreased; the heat resistance of fluorined epoxy resin decreased a little. The alkali resistance, water resistance, hydrophobicity and mechanical properties of epoxy resin cured by DDM were better than that cured by DETA, the acid resistance of epoxy resin cured by DETA increased and the thermal properties were lose a little.