B. Del Curto
Politecnico di Milano,
Keywords: recycled cellulose fibres, biodegradable and recyclable material
Summary:Environmental, economic, technical and legislative issues can be considered drivers for the development of bio-based and/or biodegradable plastics. According to this numerous studies have been focused on the development of packaging materials based on circular polymers filled with natural fibres. The research is focused on the development of an innovative eco-composite material based on circular polymers reinforced with cellulose fibres: Poly-paper is a biodegradable and recyclable material that can be processed as a conventional thermoplastic polymer, but recyclable into paper and cardboard recycling chain. The selected matrix for the composite formulation is polyvinyl alcohol (PVA), a polymer-based material with water soluble properties and forming non-toxic composites. The reinforcement selected is insoluble and recycled cellulose fibres (MFC), are used in increasing percentages up to 60% w/w, to ensure and increase the mechanical and recycling properties of the eco-composite. Different formulations have been processed by extrusion and compression moulding in order to characterize it and test its processability. A final experimental session aimed at verifying the recyclability of Poly-paper in the cellulosic recycling channel. Mechanical tensile test results exhibited a good stress-strain behaviour as well as a close correlation between cellulose fibres content and tensile proprieties: Young modulus showed 10-folds increase from 10 to 60 % w/w cellulose content (from 47,3 ± 3,22 MPa to 1155 ± 18,2 MPa). Results have shown a good experimental processability that has been optimized in the definition of process steps and temperatures. The new composite was called “Poly-paper” because it brings together the main properties of two materials families that play a key role in today’s packaging: processability of plastics and virtuous recycling in the chain of paper. Poly-paper specific application is related to packaging industry: it can replace various plastic components in a responsible way and it can be easily integrated and recycled with paper and cardboard packaging. This approach will enable the use and development of materials with improved mechanical, functional, environmental, expressive properties that led to the design of innovative applications in a sustainable scenario. ACKNOWLEDGMENT Financial support: Funding was received from the Bando Congiunto INSTM - Regione Lombardia 2016, Project Green Pack: materiali sostenibili per il packaging.