Interfacial adhesion in glass-fiber thermoplastic composites processed from acrylic reactive systems, a multi-scale experimental analysis

Interfacial adhesion in poly (methyl methacrylate) (PMMA)/glass fiber (GF) composites which are processed by in-situ polymerization of an acrylic reactive mixture, has been studied at both micro- and macro-scales. On one hand model systems were evaluated at microscale using the microbond test. On the other the 15 degrees off-axis tensile test was used to assess the fiber/matrix interfacial adhesion at macroscale in real-sized thermoplastic (TP) composite parts. For each test, reference epoxy/GF samples were characterized alongside PMMA/GF composites. Results demonstrate that the fiber/matrix interfacial strength in PMMA/GF reaches 60% and 75% of the epoxy reference value at micro and macroscale, respectively. It proves the consistency of analyses at both scales. Thus, a micromechanical analysis relying on the microbond test appears as a reliable tool to estimate the fiber/matrix interfacial bond strength which is experienced in real-sized parts. Overall results also highlight the interest of manufacturing GF/PMMA composites through a reactive process to yield parts exhibiting strong interfacial properties. It may be promising for the development of thermoplastic solutions for structural composite applications.