Enhanced Mode I fracture toughness of UHMWPE fabric/thermoplastic laminates with combined surface treatments of polydopamine and functionalized carbon nanotubes

摘要

Thermoplastic matrix-based polymer composite materials are extensively used in various application in aerospace, marine, automotive and especially in defense armor. Ultra-high-molecular-weight polyethylene (UHMWPE) fiber/fabric plays a vital role in armor application due to its high energy absorbing capability during the event of an impact. Combining thermoplastic UHMWPE fiber and Methyl Methacrylate (MMA) based liquid thermoplastic matrix (Elium (R)) which has the infusible capability at room temperature forms a complete thermoplastic polymeric composite system. However, strong fiber and matrix adhesion are essential in determining the delamination resistance of such a composite system during different modes of loading. Surface treatment by simple deposition of polydopamine (PDA) with 0.03 wt% of MWCNT (functionalized multiwalled carbon nanotubes) on the fiber surface can improve the bonding between the fiber and matrix. Results from double cantilever beam (DCB) test at 1 mm/min shows 19.6% and 42.5% improvement in mode 1 interlaminar fracture toughness (G(1c)) for PDA surface-treated sample and PDA with embedded 0.03 wt% of MWCNT respectively when compared with that of a common composite. The microstructural study from SEM image on the fractured surface shows the improved G(1c) is due to the crack-blunt mechanism at the crack-tip due to the influence of strong fiber/matrix adhesion after PDA+CNT surface treatment and also due to the high ductile nature of thermoplastic Elium (R) matrix.