Effect of Epoxidized Natural Rubber on the Performance of Soybean Meal Adhesives
[Objective]With soybean meal(SM)as the main raw material,the double cross-linked network structure was constructed to improve the water-resistant bonding performance and the toughness of the cured adhesive layer of SM adhesive,which provided theoretical basis and technical guidance for the industrial application of soybean meal adhesive.[Method]Epoxidized natural rubber(ER)and glycerol triglycidyl ether(PTGE)were used to construct a double cross-linked network structure in soybean meal adhesive system.The effects of ER with different epoxy values on the chemical composition,viscosity,moisture uptake,residual rate,thermal stability,and cross-section morphology of modified SM adhesive were studied,and the wet shear strength of the prepared poplar plywood was characterized.[Result]1)ER-50 with 50％epoxy value and PTGE(epoxy crosslinking agent)were used to modify SM adhesive.The wet shear strength of the modified SM adhesive(SMP/ER-50)was 1.02 MPa,which was 292.3％higher than that of the control group and reached the national standard of class Ⅱ poplar plywood.2)It was observed by scanning electron microscope that the cross-section of the cured adhesive layer of SMP/ER-50 adhesive appeared to have a uniform phase separation structure,which effectively improved the toughness of the adhesive.3)SMP/ER-50 adhesive had excellent water resistance,and its residual rate was 90.54％,which was 26.65％higher than that of the control group.The moisture uptake was 19.28％,which was 14.99％lower than that of the control group.[Conclusion]The main reason for the improvement of water resistance and toughness of SMP/ER-50 adhesive was that PTGE and ER-50 formed a dense double cross-linking network structure in the adhesive system,which prevented water immersion and improved the water resistance of SMP/ER-50 adhesive.In the double cross-linking network,ER absorbs part of the stress and dissipates the energy when subjected to external force,thus achieving the toughening and strengthening of the SMP/ER-50 adhesive.
国家科技期刊平台
NSTL
万方数据
