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

Unidirectional (UD) hybrid composite laminates based on glass fibers ( GF) and high performance polyethylene fibers (PEF) were prepared with partially polymerized methyl methacrylate (MMA) at room temperature, f ollowed by heating at 55 degrees C (well below the softening point of PEF) for 2 h. The total volume fraction of fibers of the hybrid compos ite was held constant and the proportion of PEF or GF was varied. The viscoelastic behavior of the hybrid composite was studied through dyna mic mechanical analysis at different relative volume fractions of PEF. Parameters such as storage modulus (E'), loss modulus (E''), and loss factor or damping efficiency (tan delta) were determined in a resonan t frequency mode. All the properties were compared between the hybrid composites. It was found that the glass transition temperature (T-g) i ncreased to a higher region with the increase in relative volume of PE F. It was also observed that the efficiency of the hybrid composite in creased with the increase in relative volume of PEF. (C) 1996 John Wil ey & Sons, Inc.