Dissolution recycling for recovery of polypropylene and glass fibres

Abstract

The push for increasing the recycling of plastics is intensifying, and the growing use of composites creates a need to increase the recyclability of polymer composites at their end-of-life. As opposed to thermal and chemical recycling techniques, recycling by dissolution has the benefit of enabling the recovery of both fibre and matrix from thermoplastic composites without altering their chemical composition. In this study, suspensions of polypropylene and glass fibres of varying concentrations were obtained upon dissolution in xylene heated to 130 °C. Subsequent filtration enabled the separation and recovery of both clean fibre and polypropylene fractions. The chemical structures of both fractions were identified by Fourier transformed infrared spectroscopy as pure polypropylene and clean glass fibres. The recovered glass fibres contained 1 wt% organic material from glass fibre sizing, and the recovered and pristine polypropylene showed no sign of remaining fibres.