Characterization of Interlaminar Fracture Properties of Advanced Polymer Matrix Composites Interleaved With Buckypaper

Recently a novel high-speed/high-yield surfactant-free manufacturing method has been developed for manufacturing of large size buckypaper. In spite of this development, there is no data on the effects of microstructural characteristics on the structural properties of surfactant-free buckypaper based nanocomposites. This investigation examines the effects of the proposed manufacturing procedure on the resultant interlaminar fracture properties of buckypaper based nanocomposites. Buckypaper samples were fabricated using the novel surfactant-free technique. Buckypaper based nanocomposite samples were subjected to mode I, II, and I-II fracture testing in Double Cantilever Beam (DCB ), End Notched Flexure (ENF) and 4-point End Notched Flexure (4ENF), and Mixed Mode Bending (MMB) configurations, respectively. Analysis of the test specimens in terms of mode I energy release rates showed good agreement among Modified Beam Theory, Compliance Calibration, and Modified Compliance Calibration methods. ENF and 4ENF tests gave very consistent crack initiation and propagation results for mode II fracture. The fracture envelope function of the composite and the nanocomposites was developed as a design guideline for nanocomposite materials.