Morphological study and mechanical property of epoxy-foam adhesives based on epoxy composites for automotive applications

The challenge of developing epoxy-foam adhesives for automotive applications lies in the difficulties associated with finding the optimal composition ensuring both high expansion ratio and mechanical strength. Herein, epoxy-foam adhesives based on epoxy composites were prepared and evaluated for automotive applications. The curing behavior was studied by differential scanning calorimetry, and the morphology was characterized non-destructively by micro X-ray computed tomography. Increasing the content of rubber-modified epoxy (RME) retarded the curing reaction by increasing the expansion ratio and affected the lap shear strength. A high expansion ratio and suitable mechanical strength was observed for epoxy-foam adhesives containing 10 or 15 wt% RME.