Study On Modification Of Epoxy Resin E-51 For Low Temperature Composite

The epoxy resin was widely used in aviation,adhesive and many fields.But it is very brittle,easy to crack and poor impact resistance at low temperatures,which limits the application of epoxy resin.Thus,this paper we developed several modifiers to modificate the epoxy resin system and then improve the mechanical properties of system.The Fourier transform infrared spectrometer(FTIR),scanning electron microscope(SEM),differential scanning calorimetry(DSC),thermogravimetric analyzer(TGA),electronic universal testing machine test was employed to characterize microscopic section structure and toughening mechanism of modified epoxy resin.1.The N,N,N',N'-acrylic acid polyglycol ester ethyl amine was used to modify the epoxy system.The results showed that N,N,N',N'-four amino ethyl acrylate polyethylene glycol ester can effectively enhance the toughness of epoxy resin and its performance in low temperature.When 15%wt of the N,N,N',N'-acrylic acid polyglycol ester ethyl amine was added in the epoxy system,the performance of epoxy resin at low temperature got the biggest improvement.The glass transition temperature reduced and the tensile strength at low temperature increased 45.39%and the flexural strength increased 64.82%,while the thermal stability without too much change.2.The starch achieved good effect to modify the epoxy resin.The starch soluble in polyethylene glycol-400 was added into the epoxy resin system,which can reduce the cost and toxicity of epoxy resin system.The results showed that the modification agent content is 15%wt,the tensile strength of epoxy resin system at low temperature will increase 312.42%,the bending strength at low temperature will increase 279.43%,its glass transition temperature was reduced by 40.33%and the thermal stability of materials only slightly decrease.3.With flexible side chain containing starch macromolecules(starch,polyethylene glycol ether)acrylate to modify epoxy resin can obtain very good modification effect.The starch into the epoxy resin system can greatly reduce the cost and toxicity of epoxy resin system.The results showed that when the modification agent content is 10%wt,the tensile strength of epoxy resin system at low temperature will increase 206.74%,the bending strength at low temperature will increase 298.36%,the glass transition temperature was reduced by 34.44%,and the thermal stability of materials only slightly decrease.4.In order to flexible side chain on the epoxy resin,we through the reaction of hydroxy in poly(maleic acid polyglycol ester)and epoxy groups in epoxy resin.The results showed that poly(maleic acid polyglycol ester)can effectively enhance the toughness of epoxy resin and its low temperature performance,when the poly(maleic acid polyglycol ester)addition amount was 5%wt,the performance of epoxy resin at low temperature get the biggest improvement.The glass transition temperature was reduced by 17.82%,the tensile strength of epoxy resin system at low temperature will increase 269.00%,the flexural strength increased 162.73%.5.We made a kind of flexible three block copolymer to modify epoxy resin system by using methyl acrylic acid,polyethylene glycol(peg)and vinyl acetate.In order to flexible side chain on the epoxy resin,we through the reaction of hydroxy in poly(maleic acid polyglycol ester)and epoxy groups in epoxy resin.The results showed that this kind of flexible three block copolymer can greatly improved the mechanics properties of epoxy resin.When the modification agent content is 15%wt,the tensile strength of epoxy resin system increased 69.65%at room temperature,while increased 145.33%at low temperature.when the modification agent content is 10%Wt,the cold bending strength of epoxy resin system increased 93.34%.The bending strength of epoxy resin system at low temperature increased 283.47%when modification agent content is 5%.The glass transition temperature of epoxy resin system was reduced 29.8%,the thermal stability was not significantly reduced.6.We also modified epoxy resin with a block copolymer containing starch.We made block copolymer with corn starch,methyl acrylic acid and polyethylene glycol-400 as raw materials to modify epoxy resin.The results showed that this kind of block copolymer can greatly improve the mechanical properties of the system,on the premise of slightly lower thermal stability system.When the modification agent content is 10%wt,the tensile strength of epoxy resin system at low temperature increased 349.60%;When the modification agent content is 15%wt,the bending strength of epoxy resin system at low temperatures increased 253.23%.The glass transition temperature of system reduced 40.35%.