| Application of epoxy resin adhesives are widely because they have the advantages of high adhesion strength,excellent insulation,resistance to attack and dimensional stability.The room temperature fast-curing epoxy resin adhesive make the operating environment become simply,and greatly improved the construction efficiency.Mercaptan curing agent can quickly react to epoxy resin at room temperature with tertiary amine accelerators.At present,the Mercaptan curing agent mainly depends on imports in the domestic market,and have widespread problems such as low adhesion strength and obvious yellowing of cured products.The paper starts from the structural design of Mercaptan curing agent,make a study of high adhesion strength and colorless transparent rapid curing epoxy resin adhesive,have a very broad prospects of application.In this paper,four different structures of polythiol compounds A,B,C and D were prepared,and the optimal conditions of the reaction process were determined by the test of FTIR,NMR and epoxy value.The thiol value,viscosity and curing system performance of the reaction products were tested.The results showed that reaction product A had the best effect as curing agent.The viscosity at room temperature was 19000 mPa·s,the thiol value was 0.43 mol/100g,the gelation time was about 5 min,and the adhesion strength was higher than the others.A rapid curing epoxy resin adhesive with high adhesion strength was prepared with polythiol A as the experimental object and DMP-30 as the accelerator.The effect of epoxy resin content,accelerator content on tensile shear strength,heat resistance of cured product,water resistance,curing reaction process and curing reaction kinetics were tested.The results showed that when the ratio of epoxy resin to curing agent A is 0.8:1,and the content of accelerator DMP-30 is 5%,the gelation time of the curing system was about 5 minutes,and the maximum tensile shear strength reached 25 MPa.The curing reaction had the fastest reaction rate in the first 10 min,the reaction proceeded to 40 min and entered the post-cure process.Compared with the traditional aliphatic room temperature curing agent,the curing time was significantly shortened.which was significantly shorter than the curing time before the traditional fat group room temperature curing agent.The curing reaction kinetics model was obtained by non-isothermal DSC method and the optimal cure temperature for deriving the curing reaction is 35.37?.Using polythiol A as the experimental object,a colorless transparent rapid curing epoxy resin adhesive was prepared by improving the adhesive formulation.Effect of different accelerators on the properties of cured products were tested.The results showed that the curing reaction rate is fast when the triethylenediamine is used as accelerator,and the cured product is colorless and transparent.Based on this,the influence of the triethylenediamine content of the accelerator on the tensile shear strength,the influence of the curing temperature on the transparency,the water resistance of the cured product,the curing reaction process and the curing reaction kinetics were tested.The results showed that when the content of triethylenediamine was 0.8%,the gelation time of the curing system was about 5 minutes,and the tensile shear strength reached 17 MPa.The curing reaction rate is the fastest in the first 5 minutes,the curing reaction rate is gradually reduced from 5 minutes to 30 minutes,and the curing reaction enters the post-curing process after 30 minutes,the pre-curing time is significantly shortened.The curing reaction kinetics model was obtained by non-isothermal DSC method and the optimal cure temperature for deriving the curing reaction is 35.37?. |
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