Interface Bond Improvement of Sisal Fibre Reinforced Polylactide Composites with Added Epoxy Oligomer

Abstract

To improve the interfacial bonding of sisal fiber-reinforced polylactide biocomposites, polylactide (PLA) and sisal fibers (SF) were melt-blended to fabricate bio-based composites via in situ reactive interfacial compatibilization with addition of a commercial grade epoxy-functionalized oligomer Joncryl ADR@-4368 (ADR). The FTIR (Fourier Transform infrared spectroscopy) analysis and SEM (scanning electron microscope) characterization demonstrated that the PLA molecular chain was bonded to the fiber surface and the epoxy-functionalized oligomer played a hinge-like role between the sisal fibers and the PLA matrix, which resulted in improved interfacial adhesion between the fibers and the PLA matrix. The interfacial reaction and microstructures of composites were further investigated by thermal and rheological analyses, which indicated that the mobility of the PLA molecular chain in composites was restricted because of the introduction of the ADR oligomer, which in turn reflected the improved interfacial interaction between SF and the PLA matrix. These results were further justified with the calculation of activation energies of glass transition relaxation (∆Ea) by dynamic mechanical analysis. The mechanical properties of PLA/SF composites were simultaneously reinforced and toughened with the addition of ADR oligomer. The interfacial interaction and structure–properties relationship of the composites are the key points of this study.

Toughness Enhancement of PHBV/TPU/Cellulose Compounds with Reactive Additives for Compostable Injected Parts in Industrial Applications

“…Some reports have been found in the literature about the use of diisocyanates as compatibilizers in biopolyester/fibre composites [ 29 , 30 , 31 ], PHBV/polylactic acid (PLA) blends [ 32 ], and PLA/TPU blends [ 33 , 34 ], showing good improvements in interfacial adhesion. Hao et al showed improved interfacial adhesion in PLA/sisal fibre composites using Joncryl ® [ 35 ] and Nanthananon et al reported similar improvements in PLA/eucalyptus fibre systems [ 36 ]. Furthermore, the use of Joncryl ® has also been proved efficient in the compatibilization of POM/TPU blends [ 37 ].…”

Peer Review #2 of "Effects of alkali treatment on the mechanical and thermal properties of sisal/cattail polyester commingled composites (v0.1)"

“…Weak interfacial compatibility in composites also accelerates matrix crack propagation, resulting in debonding of fibers and matrices (Rizal et al, 2018). Further, fiber-matrix interface conditions often affect energy absorption in composites, in that composites with good interfacial compatibility always have the impact load received by the polymer matrix transferred to the fiber (Hao, Wu, Qiu, & Wang, 2018;Nair, Wang, & Hurley, 2010) which is its role in matrix reinforcement. Impact failure of composites are caused by fiber and matrix damage, fiber pull-outs from the matrix, and debonding between the fiber and matrix.…”

Additive Manufacturing: A Novel Method for Developing an Acoustic Panel Made of Natural Fiber-Reinforced Composites with Enhanced Mechanical and Acoustical Properties

“…Ibrahim et al experimented with kenaf fibers as reinforcement in PLA as a polymer matrix by the melt blending technique [138]. Hao et al melt-blended PLA as a polymer matrix with sisal fibers as a reinforcement and epoxy as a binder and concluded that the composite exhibits improved interfacial bonding [139]. Composites with enhanced mechanical properties are produced by the melt blending technique [61].…”