Interfacial shear strength of flax fiber/thermoset polymers estimated by fiber fragmentation tests

Interfacial shear strength (ISS) of flax fibers subjected to different treatments and thermoset polymers, derived from SF tests was investigated using comprehensive fiber strength data. Two types of single fiber composite (SFC) specimens were manufactured and tested differing in fiber and hence SFC gauge length. An extensometer was used to measure applied strain, while for short-fiber SFCs the strain was evaluated from grip displacement corrected for setup compliance. It was concluded that the adhesion of the enzyme-retted elementary flax fibers and thermoset matrices do not benefit from the common surface treatment.