Sustainable Epoxy Composites with UV Resistance Based on New Kraft Lignin Coatings

• Published in: Molecules (Basel, Switzerland) Vol. 29; no. 15; p. 3697
• Main Authors: Seoane-Rivero, Rubén, Ares-Elejoste, Patricia, Gondra, Koldo, Amini, Sara, de Hoyos, Pedro-Luis, Gonzalez-Alriols, Maria
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05.08.2024
• Subjects: Analysis; biobased; Carbon footprint; composite; Composite materials; epoxy; Epoxy resins; Green market; kraft lignin; Lignin; Lignocellulose; Mechanical properties; Molecular weight; Paper industry; Polymers; Raw materials; Spectrum analysis; sustainable; Sustainable materials; UV resistance; Spain; kraft lignin; UV resistance; biobased; sustainable; composite; epoxy
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules29153697

Currently, the composite industry is focusing on more environmentally friendly resources in order to generate a new range of biobased materials. In this manuscript, we present a new work using lignocellulosic wastes from the paper industry to incorporate into biobased epoxy systems. The manufactured materials were composed of kraft lignin, glass fiber, and a sustainable epoxy system, obtaining a 40% biobased content. Using a vacuum infusion process, we fabricated the composites and analyzed their mechanical and UV resistance properties. The findings reveal a significant correlation between the lignin content and flexural modulus and strength, showing an increase of 69% in the flexural modulus and 134% in the flexural strength with the presence of 5% of lignin content. Moreover, it is necessary to highlight that the presence of synthesized lignin inhibits the UV degradation of the biobased epoxy coating. We propose that the use of lignocellulosic-based wastes could improve the mechanical properties and generate UV resistance in the composite materials.