EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The increasing world population and waste production, together with the excessive levels of resource extraction, generate a growing demand to move the society towards a circular bio-economy and to use environmentally friendlier materials. Therefore, the development of greener materials and the use of waste materials as raw materials are of great interest. The aim here is to produce laminated biocomposites based on poly(lactic acid) (PLA) and recovered lignocellulosic fibres (RF) from municipal solid waste (MSW) with thermo-mechanical properties that can compete with commercial fossil fuel-based polymers and/or can fulfill the recent government demands of producing recyclable materials for packing or at least with 30% of recyclable material.

In this work, RF networks were produced by bleaching and refining the fibres, followed by vacuum filtration and heat consolidation in a hot-press at 120 °C for 30 min under a weight of 1 t. Fibre networks with a grammage of ~ 100 gm−2 were produced. Thin PLA films were prepared from pellets by hot-press. Model recovered fibre-reinforced PLA laminated composites were produced by stacking the RF networks together with the thin PLA films and compression moulded at 190 °C for 5 min under a weight of 1 t. PLA composites showed a flexural modulus of ~ 6.4 GPa, while neat PLA possesses a flexural modulus of 4.6 GPa. The flexural strength and strain of neat PLA were measured to be 100 MPa and 3% and were not significant affected with the incorporation of recovered fibres. The results show an increase of 40% of the PLA stiffness by the incorporation of ~ 35 w.t% of recovered fibres without sacrificing the flexural strength and strain of neat PLA. The further mechanical and thermal characterization will be carried out and the recyclability of the municipal solid waste recovered fibres-reinforced PLA composites laminates will be studied.