Effect of the Physicochemical Properties of Starch Adhesives on the Mechanical Properties of Composites from Cellulosic Materials Doped with Rust
Olaoluwa Ayobami Ogunkunle,
Titilope Temidayo Olugbenga,
Oluwamumiyo Dorcas Adeojo
Issue:
Volume 7, Issue 1, June 2023
Pages:
7-18
Received:
5 March 2023
Accepted:
30 March 2023
Published:
25 May 2023
Abstract: The study examined the potential use of starch obtained from cassava and yam sources for the production of stable industrial adhesives that can be utilized in the production of composites. Cassava and yam tubers used in the study were obtained from Mowe and Ile-Ife (both in southwestern Nigeria) and washed free of sand and impurities before sun-drying. Starch and protein were then extracted from the cassava and yam tubers. The results indicated that both cassava and yam starches were suitable for this purpose. However, the particle size of the starch granules was found to be an important factor in determining the physicochemical properties of the adhesive. Composites produced with cassava starch adhesive were found to be more resistant to moisture than those produced with yam starch. Additionally, cassava adhesive was able to utilize more lignocellulosic fibers while still maintaining stability, provided that its limit was not exceeded. Furthermore, the addition of 2% metal additive (Fe3+ ions) improved the properties of the composites through coordination. Cassava starch-based composites were found to exhibit higher crystallinity than those produced with yam starch. The adhesive produced from these starch samples was found to be competitive with formaldehyde-based resins, with the added advantage of being non-toxic and capable of neutralizing the protons of acids with their excessive hydroxyl groups. Overall, the use of these cellulosic materials in the production of composites presents an environmentally friendly solution to the problem of waste and pollution. The study findings suggest that the starting materials are inexpensive, widely available, and environmentally friendly, and that they can produce products of greater economic importance.
Abstract: The study examined the potential use of starch obtained from cassava and yam sources for the production of stable industrial adhesives that can be utilized in the production of composites. Cassava and yam tubers used in the study were obtained from Mowe and Ile-Ife (both in southwestern Nigeria) and washed free of sand and impurities before sun-dry...
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Mechanical Potential of Adhesives Elaborated with the Gramineae Stem Lignin
Karga Tapsia Lionel,
Dawoua Kaoutoing Maxime,
Noel Konai,
Ndiwe Benoit,
Tawe Laynde,
Njom Abel,
Danwe Raidandi
Issue:
Volume 7, Issue 1, June 2023
Pages:
19-27
Received:
17 June 2023
Accepted:
10 July 2023
Published:
20 July 2023
Abstract: The aim of this work is to valorize local materials and to replace synthetic resins in the wood industry with biodegradable resins made from renewable resources such as the dry stems of herbaceous plants. Klason extracted the gramineae stem’s lignins of Andropogon gayanus and Sorghum bicolor and then Soda methods then characterized using attenuated total reflectance Fourier transform spectra in the 4000 and 400 cm-1 range. Their decompositions were studied using Thermogravimetric Analysis. Their yield from lignins extractions are respectively 19.26% and 24.9%. Guaiacyl, Syringyl, p-hydroxyphenylpropane, phenols and secondary alcohols are present in these lignins. The gel times of their adhesive using paraformaldehyde as hardener decreases as the pH increases. At pH=12, these gel time values are, respectively 6.6 and 7 minutes. These lignins begin to decompose at 291°C. The Modulus of elasticity was studied by thermomechanical analysis and wood particleboards were prepared bonded with these resins. The stiffness of Andropogon gayanus lignin resin is better than that of Sorghum bicolor (4339.08 > 3767.87MPa). The Internal Bond strength of Particleboards manufactured with 10% of total adhesive solids on dry wood particles are respectively 0.37 and 0.41 MPa. These two lignins are good for wood adhesives. The average MOR and MOE values for the manufactured Andropogon gayanus and Sorghum Bicolor particleboards are respectively 14.51MPa and 1850.6MPa and 16.5MPa and 2053.4MPa. The manufactured particleboards have a low resistance to humidity and that they can only be used in a dry environment.
Abstract: The aim of this work is to valorize local materials and to replace synthetic resins in the wood industry with biodegradable resins made from renewable resources such as the dry stems of herbaceous plants. Klason extracted the gramineae stem’s lignins of Andropogon gayanus and Sorghum bicolor and then Soda methods then characterized using attenuated...
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. Quantum Espresso software is used to study the superconductivity of the structure, when the μ*=0.10, election-phonon coupling parameter λ=0.4112, the critical temperature of superconductivity is 2.77 K, and the bands structure and the density of states of LiBC are obtained by the software. The structure and the superconductivity are also studied under some high pressure.