Design And Synthesis Of Amide Bifunctional Ionic Liquid Curing Agent

In order to convert the epoxy resin into a crosslinked network with certain heat resistance,thermo-mechanical properties and mechanical properties,the curing agent is an essential raw material.Traditional amine hardeners have such problems as high volatility,high toxicity,high melting point,poor compatibility with epoxy resin,poor color and color of materials,and easy to be oxidized by air.Ionic liquid has excellent physical and chemical properties such as low melting point and moderate polarity.As a curing agent,ionic liquid can improve the compatibility,flame retardancy,wear self-healing and mechanical properties of epoxy resin materials,and extend the application period of epoxy resin materials.In the early stage,we designed and synthesized a series of functionalized ionic liquid curing agents of amides and proved them to be a high temperature resistant and rapid curing agent of epoxy resin.(1)Designed and synthesized a series of dual functional amide kinds of ionic liquids as curing agents of epoxy resin,such as 1-(3-amino-3-oxygen propyl)-3-allyl-imidazole salt,1-(3-amino-3-oxygen propyl)-3-(2-amino-2-oxygen generation was synthesized ethyl)-imidazole salt and 1-allyl-3-(2-amino-2-ethyl oxygen generation)-imidazole salt and cyanogen amine(N(CN)2)or double(three methyl sulfonyl fluoride)imide(NTf2)anion,and completes the characterization of physical and chemical properties.(2)The curing behavior of two-function ionic liquid epoxy resin TDE-85(4,5-epoxy-cyclohexane-1,2-diglycidyl dicarboxylate)was studied.The results show that the prepared dual-functional amine ionic liquids can be used as medium or high temperature curing agents for TDE-85,the curing temperature ranges from 130 to 208°C,and the optimal mass ratio ranges from 15:100 to 40:100.The kinetic analysis results of the bisamide curing agent 2b/ TDE-85 system determined by differential scanning calorimeter DSC showed that the system of bisamide curing agent2b/ TDE-85 system had the lowest Ea(Ek = 8.38 k J/mol,Eo = 9.58 k J/mol),indicating that the reactivity of bisamide curing agent and epoxy resin was the highest.The high reactivity of bisamide curing agent with epoxy resin may also be related to the high crosslinking density of 15597mol/m3.(3)The thermal resistance of two-function ionic liquid and epoxy resin TDE-85 cured castable was studied.The results showed that the glass transition temperature was212?,the decomposition temperature was 403?,and the decomposition temperature at5% and 10% was 338 and 356?.(4)The curing mechanism of 1-(3-amino-3-oxypropyl)-3-(2-amino-2-oxyethyl)-imidazole NTf2 and TDE-85 was revealed: when the curing agent of bisamide and epoxy resin TDE-85 were mixed at 60 ?,the reaction of-NH2 group and epoxy ethane resulted in hydroxy-OH and secondary amine.As the temperature rose to 208?,more-OH groups and tertiary amines were formed with the epoxy ring.When the temperature rises to 271?,-OH reacts with the ethylene oxide group to form-COC-.When the resin matrix was further maintained at 330? for 2 hours,the hydroxyl groups are dehydrated and condensed to form-COC-,further forming a three-dimensional cross-linked network.