Recyclability and Characterization of Co-Extruded Multilayer Fuel Tanks 980096

The recyclability of co-extruded multilayer fuel tanks, and characterization of the materials used in their manufacture, have been investigated. The ethylene-vinyl alcohol, EvOH, copolymer barrier layer, extruded as a sandwich between two adhesive layers of a maleated linear low density polyethylene, LLDPE, is surrounded by three high density polyethylene, HDPE, layers, one of which is composed of the regrind derived from the waste generated by manufacture. Particular attention has been focused on the mechanism of adhesion between the barrier layer and the adhesive layers. Surface analysis of the in situ surfaces has confirmed the formation of chemical bonds between the two polymers. Morphological information, concerning dispersion of the barrier layer in the HDPE matrix during recycling, has been obtained by scanning (SEM) and transmission (TEM) electron microscopy techniques. Mechanical performance, measured by driven dart impact strength and tensile properties, indicate that the recycling of these components is technically feasible. A preliminary evaluation of recycled material, that had been equilibrated upon exposure to fuel, indicated that the fuel had a negligible influence on the morphology and properties blend.