Synergistic effect of cryogenic surface modification on flax fiber and dispersion of MWCNT at the interface of flax/DGEBA composite

Abstract

This study investigates the development of sustainable flax/Diglycidyl ether Bisphenol-A (DGEBA) composite enhanced through cryogenic surface treatment of flax fibers and the dispersion of Multi-walled carbon nanotubes (MWCNT) in the polymer matrix. The methodology involves modifying flax fibers via cryogenic treatment to improve surface topology and thermal stability, alongside incorporating MWCNT into the DGEBA polymer to enhance composite properties. The effects of these modifications were evaluated through mechanical and thermal testing, focusing on tensile and flexural strengths, and degradation temperature. Results show that cryogenic treatment increases the thermal stability of flax fibers, raising degradation temperature by 10°C, attributed to an increase in hemicellulose composition. Mechanically, cryogenic-treated flax fiber composites without MWCNT demonstrated a 7.3% increase in tensile strength and a 28% increase in flexural strength. The dispersion of MWCNT in DGEBA improved tensile and flexural strength by 8.3% and 29%, respectively, in untreated flax fiber composites. When both cryogenic treatment and MWCNT dispersion were applied, tensile strength improved by 17.2% and flexural strength by 36.6%, attributed to enhanced interfacial bonding between the fiber and matrix. These findings illustrate the synergistic effects of cryogenic treatment and MWCNT dispersion, demonstrating their potential to optimize the thermal and mechanical performance of sustainable polymer composites.