실란트 조성에 따른 고분자 복합재료 간 접착력 비교 평가

Abstract

This study investigates the interfacial adhesion properties of two commonly used structural sealants, polyurethane (PU) and polysulfide (PSF), when applied to carbon fiber-reinforced polymer (CFRP) substrates with different resin matrices, PU-based and epoxy-based CFRP. The calculated work of adhesion (Wadh) values revealed that the PU sealant exhibited significantly higher surface energy and polar component than the PSF counterpart, owing to its urethane groups capable of hydrogen bonding and dipolar interaction. Shear adhesion strength tests showed that the PU sealant achieved strengths of 1.3 MPa and 0.9 MPa on PU and epoxy CFRP, respectively, whereas the PSF sealant exhibited consistently low strength (0.1 MPa). These differences were attributed to the chemical structure, polarity, and compatibility between the sealant and substrate. The findings demonstrate that interfacial adhesion is strongly influenced by both the molecular functionality of the sealant and the chemical nature of the CFRP matrix. This study highlights the importance of selecting sealants based on interfacial compatibility and structural performance requirements for reliable bonding in composite structures.