Deformation Micromechanics of a Thermoplastic—Thermoset Fiber—Matrix Interface using the Single Fiber Composite Test

The development of high performance fibers, based on polyethylene (PE) fiber opened the possibility of manufacturing composites with high strength and lightness and gave a modern application to an old fashioned material. In the present study, the interfacial micromechanics between gel-spun PE fibers and epoxy resin is studied using Raman spectroscopy. The poor adhesive properties between PE and any matrix material makes it ideal for studying the debonding process; the interfacial failure is relatively easy to promote. The study of the deformation micromechanics and failure of the thermoplastic—thermoset interface will eventually lead to the control of this type of hybrid composite, which represent a new kind of materials.

The single fiber composite geometry was used to study the interface and how it was affected by different chemical treatments on the fiber surface, which created an interface between the PE fiber and the epoxy matrix. Prior to treatment, the interaction between them was nonexistent. Stress profiles along the fiber were obtained using Raman spectroscopy and the interface performance was assessed using a partial debonding model. The results not only lead to calculation of the interfacial shear stress (ISS), but also aid in understanding the debonding process and levels of stress required for the composite interface to fail.