Study On The Preparation And Properties Of Longchain Glycidyl Ester And Its Modified Amines

Due to its unique chemical structure,epoxy resin has excellent adhesion,chemical resistance,electrical insulation and mechanical properties.It is widely used in chemical,mechanical,electronics,building materials,coatings and adhesives.Epoxy resin alone has no use value,it must react with the curing agent to form a three-dimensional network structure,in order to give full play to its performance characteristics.But the cured epoxy resin has the shortcomings of brittleness and poor impact resistance,its use is limited.Therefore,toughened epoxy resin research is an important issue.In this paper,long-chain dimer acid diglycidyl ester and oleic acid glycidyl ester were prepared by two-step method of esterification and cyclization,using the single-factor controlled variable method to explore the best synthesis conditions,and the products were characterized using infrared spectroscopy and elemental analysis.Dimer acid diglycidyl ester prepared in this study was the yellow transparent liquid with the epoxy value of0.2365mol/100g,the viscosity of 875mPa·s,the easily saponifiable chlorine content of0.0097mol/100g,and the inorganic chlorine content of 0.0002mol/100g;oleic acid glycidyl ester was the deep yellow transparent liquid with the epoxy value of 0.2271mol/100g,the viscosity of 28.5mPa·s,the easily saponifiable chlorine content of 0.0099mol/100g and the inorganic chlorine content of 0.00016mol/100g.In this paper,long-chain dimer acid diglycidyl ester and oleic acid glycidyl ester were used as toughening agents to toughen epoxy resin.Compared with 4.33kJ/m~2 impact strength of the cured product of epoxy resin 618 with isophoronediamine,the impact strength of the cured products of 618 and dimer acid diglycidyl ester or oleic acid glycidyl ester in a mass ratio of 1:1 with isophoronediamine respectively reached 30.54kJ/m~2 or 16.40kJ/m~2.The impact strength of the cured product had been significantly improved after toughening,which confirmed that the long-chain glycidyl ester epoxy resin had excellent toughening effect.In this paper,isophoronediamine was respectively modified by dimer acid diglycidyl ester and oleic acid glycidyl ester.The long chain structure was introduced into the base amine curing agent to obtain a flexible curing agent.In this paper,the various factors on the amine value and viscosity of the modified amine were investigated,and the best modified amine reaction formula and process conditions were obtained.Epoxy resin was cured respectively with the glycidyl ester modified amine curing agent,isophoronediamine,glycidyl ether modified amine 593 and polyether amine D230 curing agent.And the performances of cured products were compared.The results showed that the impact strength of the cured products of epoxy resin with dimer acid diglycidyl ester modified amine or oleic acid glycidyl ester modified amine respectively reached 20.65kJ/m~2 or17.37kJ/m~2,which were higher than that of the cured products of epoxy resin with the other three curing agents,indicating that long-chain glycidyl ester modified amine had a good curing toughening effect.