Gas permeation of fibre reinforced plastics

Propulsion with liquid hydrogen or methane is under development. Storage and transportation of these fuels is part of these activities. Lightweight vessels out of fibre composites are promising candidates. Their disadvantage might be gas permeation, especially when exposed to mechanical and thermal cycling. For several applications of superconducting magnets (pulsed magnets, SQUID detectors), non-metallic and non-magnetic cryostats are required. Fibre glass composites are promising candidate materials, but again a sufficient low helium gas permeation is required. The permeation of helium, hydrogen and methane gas has been investigated. The principal arrangement for measuring gas permeation through polymers, fibre glass and carbon reinforced epoxy resins will be shown. The behaviour of coating materials or organic and metallic liners is a further topic of these measurements. Special emphasis has been put on the influence of thermal and mechanical cycling on the permeation rate. (C) 1998 Elsevier Science Ltd. All rights reserved.