Property enhancement of alternating glass/carbon fibre laminated FRP composite by glow discharge post-plasma irradiation

Conventional FRP composite suffers various problems due to improper curing, interfacial residual stress and environmental degradation. Such problems can be compensated by adopting partial use of carbon fibre in glass fibre based FRP composite and exposing such composite to energetic radiation for post-curing strengthening. Keeping this in mind, FRP composite samples with alternative glass and carbon fibre layers were irradiated through glow discharge plasma up to 35 min with air and argon maintained with 10–50 Watt power. About 113 % and 135 % increase in inter laminar and flexural strengths, respectively, were found with respect to argon plasma ageing for 30 min at 50 Watt power. At this power, about 14.7 % and 35 % increase in T_g was observed for the modified FRP with 15 min of air plasma and 30 min of argon plasma exposure, respectively. Maximum thermal activation energy was obtained through argon plasma irradiation. FTIR test revealed additional peaks at 1721 cm⁻¹ and 3060 cm⁻¹ for maximum power of argon-plasma treated FRP sample. Air and argon plasma at their optimized power and duration resulted increase in wettability with improved surface roughness. The failure modes of SEM fractographs indicated improved thermo-mechanical properties in plasma cured modified FRP.