One-Step Twin-Screw Extrusion Process to Fibrillate Deep Eutectic Solvent-Treated Wood to Be Used in Wood Fiber-Polypropylene Composites

Abstract

Bio-based wood materials are preferable for composites because of their sustainability, but adequately dispersing wood fibers in polymers can be difficult and costly. Our approach was to pretreat the wood with a green solvent system, allowing the composite to be extruded in a single step, simplifying the process, and reducing the overall cost. This study investigates the fibrillation of untreated wood sawdust (W) and deep eutectic solvent-treated wood sawdust (DESW) using a one-step twin-screw extrusion (TSE) process. The results of the analysis of wood fractions and optical microscopy confirmed that the one-step extrusion process resulted in fibrillation of both treated and untreated wood material. The width of the original wood particles was reduced by more than 99% after a one-step TSE for both untreated and DES-treated wood. The size reduction of the DESW was slightly greater than that of the untreated wood, and fibrillation was further confirmed by rheological analysis. The fibrillated wood was then compounded with polypropylene (PP) to produce a wood fiber-polypropylene composite with 50 wt % wood content. The elastic modulus of both untreated and treated extruded composites was higher than that of neat PP. The tensile strength and strain at break for the DESW-PP composite slightly increased in comparison to the untreated W-PP composite. Furthermore, DES treatment of wood resulted in a darker color and increased hydrophobicity of the material.

Review on Nonconventional Fibrillation Methods of Producing Cellulose Nanofibrils and Their Applications

“…Importantly, the crystallinity of the fiber remained the same as that of the starting materials. Separately, Taheri et al employed a potassium carbonate/glycerol DES system to pretreat wood sawdust at 100 °C for 18 h before fibrillation using TSE. It was found the DES treatment improved the degree of the fibrillation and resulted in less fiber breakage.…”

“…Importantly, the crystallinity of the fiber remained the same as that of the starting materials. Separately, Taheri et al 71 found the DES treatment improved the degree of the fibrillation and resulted in less fiber breakage. In another study, Yu et al 51 employed a choline chloride-oxalic acid dihydrate DES to pretreat Ramie fiber, followed by ball-milling.…”

Effect of acetylation modification on the structure and properties of windmill palm fiber

“…5 Short cellulose fibers with a large length: diameter ratio have been used as reinforcements in composites to improve their properties, especially mechanical strength. 10 At the molecular level, cellulose chains bear regular equatorially arranged hydrophilic hydroxy (OH) groups, 11 leading to poor dispersibility and incompatibility with other nonpolar media and matrices. 12 The blending of relatively hydrophobic polymers with hydrophilic short cellulose fibers often results in poor interfacial adhesion between the materials, leading to poor mechanical properties.…”

Effect of Acetylation Modification on Structure and Properties of Windmill Palm Fiber

“…The length/diameter ratio is more than 60 (Chen et al, 2017b). Cellulose short bers with a large length/diameter ratio have been used as reinforcement in composites to improve their behaviours, especially mechanical properties (Taheri et al, 2021). At the molecular level, cellulose chains have regular equatorially arranged hydrophilic hydroxy (OH) groups (Ishida et al, 2021), leads to poor dispersibility and incompatibility with other nonpolar media and matric (Wu et al, 2018).…”

“…At the molecular level, cellulose chains have regular equatorially arranged hydrophilic hydroxy (OH) groups (Ishida et al, 2021), leads to poor dispersibility and incompatibility with other nonpolar media and matric (Wu et al, 2018). The blending of relatively hydrophobic polymers and hydrophilic cellulose short bers often results in poor interfacial adhesion between the materials, resulting in poor mechanical properties (Taheri et al, 2021;Trinh et al, 2021).…”