基于环氧大豆油与生物基二元羧酸的胶粘剂的结构调控及其力学性能OA

In recent years,bio-based adhesives have attracted extensive attention from the scientific community.As an ideal material for preparing bio-based epoxy adhesives,epoxidized soybean oil has achieved phased research progress in the adhesive field due to its high epoxy value,wide availability,and green and low-carbon characteristics.As one of the important curing agents,bio-based dicarboxylic acids play a significant role in promoting the green and sustainable development of epoxy adhesives.In this study,epoxidized soybean oil was used as a crosslinking agent,and bio-based dicarboxylic acids with different alkyl chain lengths were used as curing agents to construct a fully bio-based adhesive system with a simple crosslinked network structure.The relationship between the microscopic crosslinked structure of the adhesive and its lap shear strength was systematically investigated.This study focused on the system with a stoichiometric ratio(R,defined as the molar ratio of carboxyl groups to epoxy groups)of 0.8.The results showed that the shorter the alkyl chain,the higher the crosslinking density of the cured product and the higher the lap shear strength of the adhesive;The longer the alkyl chain,the higher the retention rate of the lap shear strength of the adhesive under water immersion.The differences in microscopic structure were clearly manifested in the macroscopic mechanical properties:when R=0.8,the epoxidized soybean oil-glycolic acid group had the highest lap shear strength in this study,while the epoxidized soybean oil-hexadecanedioic acid group could still maintain about 55%of the initial lap shear strength after 14 days of water immersion.In conclusion,this study initially clarified the correlation between the microscopic crosslinked structure and the lap shear strength of epoxidized soybean oil-based adhesives,providing a scientific basis for subsequent research on epoxidized soybean oil-based adhesives based on structure-function relationships.