环氧树脂增强苯酚-尿素-乙二醛共缩聚树脂的粘接性能研究OA北大核心CSTPCD

In order to improve the bonding properties and water resistance of glyoxal-based resin adhesive,a new EPR-PUG multi-component cocondensation resin adhesive was synthesized using epoxy resin(EPR),phenol(P),urea(U)and glyoxal(G)as raw materials.The basic properties,curing properties,and bonding proper-ties of the resins were investigated to determine the effect of P/U/G molar ratio on the properties of the resin ad-hesive and the optimum synthetic formula.The structure and synthesis mechanism of the EPR-PUG resin adhes-ive were analyzed by contact angle,fourier infrared spectroscopy(FT-IR),nuclear magnetic resonance carbon spectroscopy(13C NMR)and X-ray photoelectron spectroscopy(XPS).The results showed that the functional groups of the raw materials were crosslinked effectively,and a dense network structure was formed among the molecules,which improved the overall performance of the resin adhesive system.Under the conditions of P/U/G molar ratio of 0.1∶1.0∶1.5,reaction pH of 4-5,reaction temperature of 70-80 ℃,reaction time of 3 h,and EPR mass fraction of 13％,the adhesive has the best performance.The dry/wet strength was 2.48 MPa,1.33 MPa(cold water),0.72 MPa(63 ℃ hot water),respectively,which meets the requirements of the national standard for class Ⅱ plywood and does not release formaldehyde.