DYNAMIC-MECHANICAL STUDY ON UNIDIRECTIONAL POLYETHYLENE CARBON-FIBERS- PMMA HYBRID COMPOSITE LAMINATES

Unidirectional (UD) composite laminates based on carbon fibers (CF) an d high-performance polyethylene fibers (PEF) were prepared with partia lly polymerized methyl methacrylate (MMA) at 25 degrees C, followed by heating at 55 degrees C (well below the softening point of PEF) for 2 h. The viscoelastic behavior of the composite was studied through dyn amic mechanical analysis at different volume fractions of the fibers. Several parameters such as the storage modulus (E'), loss modulus (E ' '), and loss factor or damping efficiency (tan delta) were determined between 40 and 160 degrees C in a resonant frequency mode. The glass t ransition temperature (T-g) increased to a higher region with increase in the volume of PEF in the hybrid laminates. It was also observed th at the efficiency of the composite decreases with increase in the volu me fraction of the fibers. (C) 1998 John Wiley & Sons, Inc.