Micro- and Nanofibrillated Cellulose (MNFC) from Pineapple (Ananas comosus) Stems and Their Application on Polyvinyl Acetate (PVAc) and Urea-Formaldehyde (UF) Wood Adhesives (original) (raw)
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Drvna Industrija, 2016
Cellulose nanofi brils (CNFs) and nano clay (NC) were selected to determine the effects of different fi llers on the characterization of poly(vinyl acetate) (PVA). Characterizations of the PVA composites obtained were studied by thermogravimetric analysis (TGA/DTG), scanning electron microscopy (SEM) and the lap joint shear strength (LJSS). The morphological studies revealed that some clumpings were observed in SEM images for 1%, 2%, and 4% wt loadings for CNFs and NC fi llers. Dispersed particle orientation morphology and the wave sheets appear to be uniformly distributed on the surface of the composites. Seen as the effects of fi llers on the thermal stability, the results showed that NC has a greater effect than CNFs, depending on the loading rates of fi llers. Lap joint shear strength generally increased after adding CNFs and NC to PVA matrix. Thus, it can be said that PVA has higher bonding performance and can be used in applications requiring higher bonding strength.
Cottonseed protein-based wood adhesive reinforced with nanocellulose
Journal of Adhesion Science and Technology, 2019
Although protein-based adhesives are eco-friendly, sustainable, and biodegradable, continued improvement in their adhesive performance is desirable. In this work, the effect of adding nanocellulose particles to cottonseed protein-based wood adhesives was studied. Cellulose nanofibers (CNF) were found to be most beneficial at about a 2% additive level, giving 22% improvement in dry adhesive strength over the cottonseed protein control. Cellulose nanocrystals (CNC) were optimal at about 10% additive level, giving 16% strength improvement relative to cottonseed protein alone. The hot water resistance of cottonseed protein isolate was also improved with CNF addition, but not with CNC addition. For comparison, soy protein isolate was also studied and showed about the same relative dry strength improvements with nanocellulose addition, but improvement of hot water resistance was less apparent. Infrared and thermogravimetric analysis suggested that the protein and the nanocellulose were interacting with each other. Thus, CNF may be a useful additive to cottonseed protein formulations used as wood adhesives.
Improvement of Poly(Vinyl Alcohol) Adhesives With Cellulose Microfibre from Sugarcane Bagasse
2011
he properties of eco-friendly adhesives prepared from poly(vinyl alcohol) (PVOH) can be improved by the use of cellulose microfibre (CMF). The CMF was prepared from oven dried sugarcane bagasse fibres. They were hydrolyzed with nitric acid of 10% (w/w). The cellulose content of the CMF increased from 44.10% to 88.99% after treatment. The CMF was added into PVOH adhesives in varied amounts of 0.5, 1.5, 2.5 and 3.5 wt% of total dry adhesive weight. The effects of CMF on chemical structure, thermal properties and crystallinity of the composite adhesives were investigated by Fourier-transform infrared spectroscopy and differential scanning calorimetry. The results showed the interactions of OH groups of PVOH with CMF molecular chains which led to increased melting point and crystallinity. In addition, the molecular weight and concentration of PVOH influenced the adhesion property of the composite adhesives. The results indicated that with the addition of CMF filler the shear strength of samples of PVOH (BF-17) of medium molecular weight increased from 1.55 to 2.41 MPa, while those of high molecular weight (BF-26) increased from 1.79 to 2.15 MPa. Furthermore, the incorporation of the CMF into the PVOH adhesives led to an improved drying time during adhesion of the test specimens.
Nanocrystalline cellulose (NCC): A renewable nano-material for polyvinyl acetate (PVA) adhesive
European Polymer Journal, 2012
In this study nanocrystalline cellulose (NCC) was used to improve the performance of polyvinyl acetate (PVA) as a wood adhesive. NCC was added to PVA at different loadings (1%, 2% and 3%) and the blends were used as binder for wood. Block shear tests were done to evaluate bonding strength of PVA at different conditions; dry and wet conditions, at the elevated temperature (100°C). The mechanical properties of PVA film and its composites with NCC were measured by nanoindentation technique. Thermal stability and structure of nanocomposites were studied by thermogravimetric analysis and atomic force microscopy (AFM). The block shear tests demonstrate that NCC can improve bonding strength of PVA in all conditions. Hardness, modulus of elasticity (MOE) and creep of PVA film were also changed positively by the addition of NCC. Thermal stability of PVA was significantly improved as NCC was added to PVA. Structural studies revealed that variations in shear strength and other properties can be related to the quality of NCC dispersion in the PVA matrix.
Nanomaterials
Sustainability and ecotoxicity issues call for innovations regarding eco-friendly adhesives in the production of biocomposite wood materials, and solutions involving nano-scale and bio-based compounds represent a valid and promising target. One possible approach is to increase the performance of adhesives such as polyvinyl acetate (PVAc) or melamine-urea-formaldehyde (MUF) by means of nanoparticles in order to obtain a material with better mechanical and environmental resistance. When applying cellulose-based nanoparticles or tannin, the concept of a circular economy is successfully implemented into the forest/wood value chain, and chances are created to develop new value chains using byproducts of forestry operations. In this study, assortments coming from young sweet chestnut (Castanea sativa Mill.) coppice stands were utilized for the preparation of single lap joint assemblies using different commercial adhesives (PVAc, MUF) and cellulose nanocrystals (CNC) and tannin as additive...
Journal of Renewable Materials, 2022
The reinforcing impact of Lignocellulosic micro and nanofibrillated cellulose (L-MNFCs) obtained from Eucalyptus Globulus bark in Urea-Formaldehyde UF adhesive was tested. L-MNFCs were prepared by an environmentally friendly, low-cost process using a combination process involving steam explosion followed by refining and ultrafine grinding. Obtained L-MNFCs showed a web-like morphology with some aggregates and lignin nanodroplets. They present a mixture of residual fibers and fine elements with a width varying between 5 nm to 20 μm, respectively. The effects of the addition of low amounts of L-MNFCs (1% wt.) on the properties of three different adhesives (Urea-Formaldehyde UF, Phenol-Formaldehyde PF, and Tannin-Hexamine TH) were studied by the evolution of the pH, the viscosity, and the mechanical properties. Results showed that the viscosity of PF and UF adhesives increased with the addition of L-MNFCs, unlike TH. Meanwhile, the addition led to better mechanical behavior for the three adhesives. Particleboards were then prepared using modified UF with L-MNFCs and tested. Results showed that an amount of 1% wt. of L-MNFCs was sufficient to increase the internal bonding by ≈67%, the modulus of elasticity by ≈43%, and the modulus of rupture by ≈29%.
Polymer Degradation and Stability, 2001
A wood adhesive was prepared from a natural renewable resource. The characteristics and optimization of starch and polyvinyl alcohol (PVOH)-based crosslinked adhesive suitable for wood-to-wood bonding in interior applications are described. The crosslinker, hexamethoxymethylmelamine (Cymel 323) produced effective crosslinking through a transetherification reaction between methoxy groups in Cymel 323 and hydroxyl groups in starch, PVOH and wood, where hydroxyl groups replaced methoxy groups forming ether bonds with the crosslinker. Optimal viscosity of the adhesive was obtained at 27% solid content. Addition of latex in the formulation increased moisture resistance. The optimum cure temperature and cure time were 175 C and 15 min. Wood samples conditioned at 93% RH for two months exhibited >95% failure in wood but little in adhesive joints. Scanning electron microscopy revealed no visible growth of fungi or other microorganisms on the adhesive after two months exposure of samples at 97% RH followed by 1 year at 50% RH. Published by Elsevier Science Ltd.
Micro-Fibrillated Cellulose in Adhesive Systems for the Production of Wood-Based Panels
Molecules
Micro-Fibrillated Cellulose (MFC) is a new type of bio-based additive, coming from wood cellulose. It can compete and substitute oil derived chemicals in several application fields. In the present work, the use of micro-fibrillated cellulose, in waterborne adhesive systems applied in the manufacture of composite wood-based panels was evaluated. Research was conducted to test the potential of improving the performance of wood-based panel types such as particleboard, waferboard or randomly-oriented strand board and plywood, by the application of MFC and the substitution of conventional and non-renewable chemical compounds. The approaches followed to introduce MFC into the adhesive systems were three, i.e., MFC 2% suspension added during the adhesive resin synthesis, MFC 10% paste admixed with the already prepared adhesive resin and MFC 2% suspension admixed with the already prepared resin. It was found that MFC improves not only the performance of the final wood panel products but als...
Utilization of Cellulose from Pineapple Leaf Fibers as Nanofiller in Polyvinyl Alcohol-Based Film
Indonesian Journal of Chemistry, 2016
Cellulose from pineapple leaf fibers as one of the natural polymer which has biodegradable property in a nanometer’s scale, can be formed as a filler in composite of Poly(vinyl) Alcohol/PVA is expected to increase the physical, thermal, and barrier properties of composite films similar to conventional plastic. The aim of this study was to examine the effect of fibrillation of cellulose fibers from pineapple leaf fibers using a combined technique of chemical-mechanical treatments, to investigate the reinforcing effect of concentration of nanocellulose fibrils in the polyvinyl alcohol (PVA) matrix on physical properties, thermal properties, water vapor transmission rate, light transmittance and morphological with and without addition of glycerol. Nanocellulose was made from cellulose of pineapple leaf fiber using wet milling (Ultra Fine Grinder). The composite film production was carried out by using casting solution method by mixing PVA solution with nanocellulose (10-50%) and glyce...