Comparative LCA of fully biobased and synthetic polymer composites accounting for fiber treatment

Given the increasing industrial use of composite materials, the reliance on synthetic fibers and petrol based polymers matrixes has raised environmental sustainability concerns. Natural fibers and bio-based polymers represent a sustainable solution that can be employed to substitute traditional composite, while maintaining high mechanical properties. This paper presents a sustainability assessment using Life Cycle Assessment (LCA), to compare traditional and innovative bio-based composite materials produced via vacuum assisted infusion and injection molding. Glass fiber reinforced polymers were selected as the reference for evaluating the environmental impact and benefits of flax fiber/bio polyester and bio polyamide composites. This study is the first to provide comprehensive inventory data on bio-polyamide production, along with a detailed sustainability evaluation of natural fiber treatments (i.e. alkali, plasma and silane treatments). In addition, it offers a novel perspective by investigating not only aesthetic components with defined geometry, but also structural parts with defined strength and stiffness requirements. Results showed significant benefits associated with the bio composites in contrast to the glass fibre reinforced composites, with impact reduction reaching up to 30 %. It was shown that raw material preparation plays a significant role in the overall impacts. Hence, switching to natural resources can contribute to the reduction of the CO 2 footprint of the composite sector. In addition, the study proved that bio composites can provide environmental benefits not only for aesthetic components but also for structural parts. • Comparison between the environmental impacts of bio based and synthetic composites. • Investigation of Vacuum Assisted Resin Infusion and Injection Molding processes. • Analysis of the production of bio polyamide (PA11) and bio polyester resins. • Evaluation of different treatments (alkali, plasma, silane) for flax fibers. • Correlation between mechanical properties of the materials and sustainability.