Mechanical testing and surface fractography were used to characterize the fracture of E-glass fiber reinforced epoxy composites as a function of the silane coupling agent used. gamma-Aminopropyltriethoxysilane (APS) and delta-aminobutyltriethoxysilane (ABS) were used because these have been shown to have different interfacial mobilities at multilayer coverage. The values of the properties studied generally increased from untreated c, as determined from a Mode I translaminar fracture toughness tests, for the untreated composites (10.5 ± 0.4 kJ/m2) was lower than that for the ABS-treated composites (14.3 ± 2.1 kJ/m2) which was lower than that for the APS-treated composites (17.1 ± 2.4 kJ/m2). Macroscopic observations showed that a larger fiber debonding area was formed in the crack tip region for the untreated glass composites, suggesting poorer bonding compared to those treated with coupling agents. Since these silanes have similar chemistry, the differences were attributed to differences in the interfacial mobility of the coupling agent layers.



Second Department

Mechanical and Aerospace Engineering


United States. Office of Naval Research
Owens Corning

Keywords and Phrases

Bending Strength; Fracture Toughness; Interfacial Energy

Document Type

Article - Journal

Document Version

Final Version

File Type





© 1999 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.