Radiation-Induced Controlled Grafting from Lignocellulosic Fiber Towards Compatibilization for Composite Reinforcement

Abstract

ABSTRACT Lignocellulosic natural fibers remain at the forefront of eco-friendly and sustainable reinforcement materials in composites. This work addresses the inherent limitations of lignocellulosic fibers in terms of their hydrophilicity and incompatibility to achieve maximum utilization in most commercial resins using a reversible addition-fragmentation chain transfer radiation-induced graft polymerization (RAFT-RIGP) approach. The one-pot surface modification technique via RAFT-RIGP was shown to efficiently graft poly(glycidyl methacrylate) onto lignocellulosic fibers like abaca. Results from the analyses of the different grafting parameters and polymerization trends reveal that the employed RAFT-mediation improved grafting yield compared to a conventional RIGP despite retardation effects inherent in the RAFT mechanism. Additionally, sufficient control over the molecular weight and dispersity of grafted chains was exhibited. The modified fibers showed improved tensile strength, higher thermal stability and reduced moisture uptake. Overall, we have demonstrated that RAFT-RIGP can be a facile, environment-friendly technique for the surface compatibilization of lignocellulose fibers without the mechanical deterioration of substrate properties, unlike other fiber modification processes. Therefore, this method has a great potential in natural fiber compatibilization for reinforcement in polymer composites.