This study evaluated reinforcing effect of waste lignocellulosic material (bagasse) and nano-SiO 2 powder on physical and mechanical properties of nano-biocomposites. In the specimen preparation, three levels of nanoSiO 2 (0, 2, and 5 wt%) and 40 wt% of fibers were used. In order to increase the interphase adhesion, polyethylene grafted with maleic anhydride was added as a coupling agent to all composites studied. The results showed that while tensile, flexural, and hardness properties were moderately improved by adding bagasse fibers and increasing nano-SiO 2 (NDS) content, Izod impact strength decreased dramatically, but fibers filled composite with 5 wt% nanoSiO 2 showed similar impact strength value to pure HDPE specimen. Natural fibers and increasing levels of nanoSiO 2 particles led to an upward trend for water absorption, while thickness swelling sharply increased and leveled off with adding these fillers. The results of study demonstrate positive effects of waste lignocellulosic material and nanoSiO 2 particles on physical and mechanical properties of composites.
In the present study, the effects of high drying temperature and UV light induced aging on bonding quality of plywood manufactured from untreated and treated veneer layers were investigated. Rotary cut veneers with dimensions of 500 mm × 500 mm × 2 mm produced from beech (Fagus orientalis Lipsky) log were selected for topochemical, chemical and mechanical analyses. The veneer sheets were oven-dried at 100°C and 180°C after the peeling process. Afterwards, the surfaces were exposed to artificial UV irradiation in an UV chamber for 24 h, 48 h and 72 h representing natural sun irradiation of 2, 4 and 6 months, respectively. Topochemical distribution of lignin and phenolic extractives of the treated and untreated veneers was investigated on a cellular level using UV microspectrophotometry (UMSP). For the chemical characterization of accessory compounds high performance liquid chromatography (HPLC) was used. Furthermore, the shear and bending strengths of plywood manufactured from the treated samples are determined in order to study the bonding quality. The UV microscopic detection shows that after high drying temperature and aging treatment, lignin condensation occurs. With increasing drying temperature and aging duration, more phenolic extractives are situated in parenchyma cells and vessel lumens which can be proved by increased absorbance at 278 nm. The HPLC analysis of the treated tissue showed distinct signals of polymerized compounds such as catechin and 2,6-dimethoxybenzoquinone which are chromophoric compounds in discolored beech wood. The mechanical properties of plywood showed that with increasing drying temperature up to 180°C does not negatively affect shear and bending strengths of samples. After exposure of the veneers to UV irradiation (especially 6 months), decreasing shear and bending strengths of plywood samples can be observed. Untersuchung des Einflusses von Hoch-Temperaturtrocknung und Alterung auf die Verklebungseigenschaften von Buchen-Furniersperrholz (Fagus orientalis)Zusammenfassung In der vorliegenden Arbeit wurden die Verklebungseigenschaften von Sperrhölzern untersucht, die aus thermisch behandelten und UV-belichteten Schälfur-nieren hergestellt wurden. Für die Untersuchungen wurden Schälfurniere der Holzart Buche (Fagus orientalis, Format 500 × 500 × 2 mm 3 ) mit Temperaturen von 100°C und 180°C thermisch behandelt und die Oberflächen anschließend 24, 48 bzw. 72 Stunden künstlich belichtet, was einer natürlichen Sonneneinstrahlung von 2, 4 bzw. 6 Monaten entspricht. Das Holzgewebe der thermisch behandelten und UV-belichteten Furniere wurde im Vergleich zu unbehandelten Schälfurnieren topochemisch mit Hilfe der zellulä-ren Universalmikrospektralphotometrie (UMSP) analysiert, um Reaktionen des Lignins und phenolischer Extraktstoffe zu detektieren. Für die chemischen Analysen der Extraktstoffe wurden zusätzlich chromatographische Untersuchungen (HPLC-Chromatographie) durchgeführt. Zur Charakterisierung der Verklebungseigenschaften wurden Sperrhölzer 498 Eur. J. Wood Prod. (2012) 70:497-506 ...
High-density polyethylene (HDPE), bagasse fibers treated by four pulping processes (AS-AQ (alkaline sulfite anthraquinone), SODA-AQ (soda anthraquinone), MEA (monoethanolamine) and chemicalmechanical pulping (CMP)), three levels of nano-SiO 2 (0, 2, and 5 wt%), and maleic anhydride polyethylene as coupling agent were used to produce pulp-plastic composites (PPCs) by injection molding. The physical and mechanical properties of corresponding composites were evaluated according to ASTM standards. The results showed that compared to untreated bagasse/HDPE composite, the addition of bagasse pulp fibers increased significantly the mechanical properties such as tensile strength and modulus, flexural strength and modulus, and hardness. The chemical pulps-reinforced composites showed better mechanical strengths than that of CMP-reinforced composites, but in some properties, CMP pulp composites have comparable results to the chemical pulp-reinforced composites. Natural fibers (untreated and treated) increased water absorption and thickness swelling of composites compared to pure HDPE. The addition of nano-SiO 2 particles showed both increasing and decreasing trends on physical and mechanical properties ofPPCs. ARTICLE HISTORY
Pulp-polylactic acid composites (PPCs) with monoethanolamine, alkaline sulfite-anthraquinone, unbleached and bleached soda bagasse pulps and polylactic acid (PLA) were successfully fabricated using twin-screw extrusion. The results were compared with bagasse flour-PLA composites (WPCs) as reference. The results indicated that the mechanical strengths of produced composites with pulp fibers were increased compared to the neat PLA and bagasse flour-PLA composites. Monoethanolamine and alkaline sulfite-anthraquinone fibers due to their surface chemical structure had a superior compatibility with PLA compared with other used bio-fibers which has been confirmed by SEM micrographs too. FTIR was used to investigate the effect of different chemical treatments on the bio-fibers. The results of XRD analysis showed that the crystallinity of PPCs was substantially improved by incorporation with pulp fibers compared to WPCs composites. The water absorption of the PPCs is different due to using the diverse bio-fibers. According to DMA analysis, the tan delta was substantially decreased when PLA was reinforced by different bio-fibers. The biodegradation of green composites were characterized and the results showed that the biodegradability of the PLA was increased due to addition of bagasse pulp biofibers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.