Back Jong-Ho, Baek Dooyoung, Shin Jae-Ho, Jang Seong-Wook, Kim Hyun-Joong, Kim Jong-Hak, Song Hong-Kyu, Hwang Jong-Won, Yoo Min-Jae
Laboratory of Adhesion and Bio-Composites, Program in Environmental Materials Science, College of Agriculture and Life Science, Seoul National University, Seoul 08826, Korea.
Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea.
Polymers (Basel). 2019 Jan 17;11(1):152. doi: 10.3390/polym11010152.
Epoxy foam adhesives are widely used for weight reduction, watertight property, and mechanical reinforcement effects. However, epoxy foam adhesives have poor impact resistance at higher expansion ratios. Hence, we prepared an epoxy composite foam adhesive with core⁻shell rubber (CSR) particles to improve the impact resistance and applied it to automotive structural adhesives. The curing behavior and pore structure were characterized by differential scanning calorimetry (DSC) and X-ray computed tomography (CT), respectively, and impact wedge⁻peel tests were conducted to quantitatively evaluate the resistance to cleavage of the CSR/epoxy composite foam adhesives under impact. At 5 and 10 phr CSR contents, the pore size and expansion ratio increased sufficiently due to the decrease in curing rate. However, at 20 phr CSR content, the pore size decreased, which might be due to the steric hindrance effect of the CSR particles. Notably, at 0 and 0.1 phr foaming agent contents, the resistance to cleavage of the adhesives under the impact wedge⁻peel condition significantly improved with increasing CSR content. Thus, the CSR/epoxy composite foam adhesive containing 0.1 phr foaming agent and 20 phr CSR particles showed high impact resistance ( = 34,000 mJ/cm²) and sufficient expansion ratio (~148%).
环氧泡沫胶粘剂因其减重、防水和机械增强效果而被广泛应用。然而，环氧泡沫胶粘剂在较高膨胀率下的抗冲击性较差。因此，我们制备了一种含有核壳橡胶（CSR）颗粒的环氧复合泡沫胶粘剂以提高其抗冲击性，并将其应用于汽车结构胶粘剂。分别采用差示扫描量热法（DSC）和X射线计算机断层扫描（CT）对固化行为和孔隙结构进行了表征，并进行了冲击楔形剥离试验，以定量评估CSR/环氧复合泡沫胶粘剂在冲击下的抗劈裂性。当CSR含量为5和10 phr时，由于固化速率降低，孔径和膨胀率充分增加。然而，当CSR含量为20 phr时，孔径减小，这可能是由于CSR颗粒的空间位阻效应。值得注意的是，在发泡剂含量为0和0.1 phr时，胶粘剂在冲击楔形剥离条件下的抗劈裂性随着CSR含量的增加而显著提高。因此，含有0.1 phr发泡剂和20 phr CSR颗粒的CSR/环氧复合泡沫胶粘剂表现出高抗冲击性（= 34,000 mJ/cm²）和足够的膨胀率（~148%）。
