Study Of Fast Curing One-component Epoxy Adhesive At Room Temperature

Epoxy resins are widely used in the field of adhesives and coatings in currently.The distinct advantages of epoxy adhesives is that they can be cured at room temperature or even at lower temperatures.The most widely used of room temperature curing epoxy adhesive is two-component adhesive,so there is a short life,high cost and so on,therefore,curing one-component epoxy adhesive at room temperature has become a hot spot at present.People usually take three aspects to improve the properties of epoxy adhesive:1,selection of the appropriate epoxy resin or combination of resins of which many are available;2.selection of the appropriate curing agent;3.Simple additions of organic or inorganic fillers.This article takes these three aspects as the starting point,a preparation of novel room temperature fast curing one-component epoxy adhesive with good curing speed,good adhesive property and excellent storage stability was achieved.Firstly,the four latent ketimine curing agent was successfully synthesized by m-xylylenediamine(MXDA)with methyl isobuty ketone(MIBK),2,4-dimethyl-3-pentanone(DIPK),2-pentanone(MIPK)and acetone(ACE)by boiling method.The structure of the synthesized ketimine was confirmed by FT-IR.The large plasticizing effect of the large ketone volume could lead to a large bond strength of one-component epoxy adhesive which epoxy adhesive prepared by ketimine protected by a large one(DIPK)with epoxy resin,tensile shear strength and flexural shear strength of 9.79MPa and 9.08MPa,respectively.The reaction conversion of the epoxide with one-component epoxy adhesive protected group by DIPK was high during storage,whereas the epoxy adhesive protected group by MIPK was low,MlBK has good storage stability and excellent curing activity.Secondly,select MXDA and MIBK as raw materials,and the effects of reaction conditions on the conversion rate of ketimine were investigated and the best ratio of ketimine to epoxy resin was explored.Results indicate that the conversion of the product can be as high as 99.2%for the reaction was achieved using a ratio of amine to ketone 1:3 at an oil bath temperature of 170?for 3 hours.The best ratio of ketimine to epoxy resin is 1:2,then,the apparent activation energy is 58.746 kJ/mol and the reaction order is 0.881.Then,metal salts doped one-component epoxy adhesive was preparation by mechanical mixing and ultrasonic treatment.It can found that the curing activity and bonding performance of 3wt%Nal-H2PO4-2H2O were highest,the lap shear strength and bending strength were increased by 48.49%and 36.14%,respectively,compared with those without addition,but slightly less storage stability.Compared with 3 wt%NaH2PO4·2H2Odoped one-component epoxy adhesive,3wt%FeCl3 and 3wt%AlCl3 doped one-component epoxy adhesives,respectively,have good curing activity and excellent storage stability.Lastly,GO-Fe and GO-Fe-P was constructed by ultrasonic.The different nanomaterials doped one-component epoxy adhesive nanocomposites at room temperature was constructed by mechanical mixing,high temperature and ultrasonic treatment,and their morphology,structure and bonding properties were characterized and analyzed.The results showed that GO-Fe-P nanocomposites had the highest curing activity,and the tensile shear strength increased from 0.65MPa(undoped)to 5.22MPa when the content was 1.0wt%,while compared with the undoped epoxy adhesive,tensile shear strength and bending shear strength increased by 55.57%and 47.95%,respectively.