Approaching a Zero-Waste Strategy in Rapeseed (Brassica napus) Exploitation: Sustainably Approaching Bio-Based Polyethylene Composites

The current need to develop more sustainable processes and products requires the study of new materials. In the field of plastic materials, the need to develop 100% bio-based materials that meet market requirements is evident. In this sense, the present work aims to explore the potential of rapeseed waste as a reinforcement of a bio-based plastic matrix that does not generate new sub-waste. For this purpose, three types of processing of rapeseed residues have been studied: (i) milling; (ii) mechanical process; (iii) thermomechanical process. In addition, the reinforcing capacity of these materials, together with the need for an optimized coupling agent at 6 wt.%, has been verified. The micromechanics of the materials have been evaluated to determine the development of these fibers in the composite material. The results obtained show remarkable increases in mechanical properties, reaching more than 141% in tensile strength and 128% in flexural strength. There is a remarkable difference in the impact behavior between the materials with milled rapeseed and the fibers obtained by mechanical or thermomechanical processes. It was found that by sustainable design it is possible to achieve a 76.2% reduction in the amount of plastic used to manufacture material with the same mechanical properties.