Characterization of E-glass–polypropylene interfaces using carbon nanotubes as strain sensors

The interfacial strength between E-glass fibers and an isotactic polypropylene matrix is evaluated in this work using single-wall carbon nanotubes as stress sensors. The carbon nanotubes were present in small quantities within an industrial sizing applied to the glass fibers. Variations in the composite interfacial strength due to the glass fibers being coated with different polymer coatings prior to composite processing were easily detected using the carbon nanotube stress sensors. These interfacial measurements correlated well with results from conventional micro-mechanical fragmentation testing.