Heat-distortion temperature of unidirectional polyethylene glass fiber PMMA hybrid composite laminates

Unidirectional (UD) composite laminates based on high-performance polyethyl ene fibers (PEF) and glass fibers (GF) and their hybrids were prepared with partially polymerized methyl methacrylate (MMA) at room temperature, follo wed by heating at 55 degrees C (well below the softening point of PEF, 147 degrees C) for 2 h. The heat distortion temperatures (HDT) of the composite s were measured and analyzed. The dependency of the KDT correlated with the wettability of the fibers, measured from the contact angle. The HDT of the composites increased with increasing GF content but decreased when PEF was used. An optimum combination of different properties was obtained by using PEF/GF/PMMA hybrid composites, with GF ply/plies on the lower tension side of the UD laminates. (C) 1999 John Wiley & Sons, Inc.