Open Access Original Research Article

Effects of Flame Retardant on the Flammability of Treated and Untreated Bagasse Papers

T. U. Onuegbu, F. O. Nnaneme, E. C. Nwokoro

Asian Journal of Chemical Sciences, Page 1-7
DOI: 10.9734/ajocs/2021/v10i119081

A comparative study of the proximate analysis, fire characteristics, and mechanical properties of the papers produced from pretreated and untreated bagasse was carried out. The bagasse collected was washed, dried, depithed and ground to pass through a 5 mm sieve using an electric milling machine. A portion was pulped without pretreatment, while others were pretreated (acetylation) before pulping and washing. After which different mass (0,2,4,6,8 and 10 g) of potassium aluminum sulphate, KAl(SO4)2.12H2O (alum) as flame retardant was added. The proximate analysis, fire characteristics and mechanical properties were determined. Results show that cellulose content increased with an increase in the concentration of potassium aluminum sulphate, while hemicellulose content increased from 24%-34% for flame retarded paper with 0-10 g concentration of alum. Lignin content also increased from 21.3%-63.2% for flame retarded paper with 0-10 g concentration of alum, respectively. Ash content varied with an increase in the concentration of potassium aluminum sulphate. Results from fire characteristics show that flame propagation and flame duration rate decreased with an increase in the concentration of alum, while ignition time and char formation increased in the concentration of alum. The mechanical properties, tensile strength, modulus and elongation at break were enhanced. Conclusively, pretreatment enhanced the properties of bagasse papers produced.

Open Access Original Research Article

Proximate, Ultimate and Calorific Analysis of European Beech Tree (Fagus sylvatica) Components for Fuel

Halil Turgut Sahin

Asian Journal of Chemical Sciences, Page 8-14
DOI: 10.9734/ajocs/2021/v10i119082

Aims: The three different above ground biomass components (branch, crown, bark) of European Beech (Fagus sylvatica) were evaluated, regarding energy and combustion properties.
Study Design: The proximate, ultimate and calorific analysis conducted on components of European Beech tree from three different age stands (10-, 20-, 30 years old). For each group of sample, separate experiments were carried out under similar conditions and experimental findings presented comparatively. The results obtained may be suggested for the selection of the best parts and age group for the improvement of fuel properties of selected tree and could provide useful evaluation of the test methods employed.

Methodology: The three different above ground biomass components (branch, crown, bark) of European Beech (Fagus sylvatica) were selected for the investigation. For comparatively determining the combustion behavior and energy properties of the of European Beech tree components, the chips were prepared. These chips were dried (air dried, 12%) in laboratory conditions at 20 °C and 50% relative humidity before being subjected to evaluations. Typically, the combustion is preceded by evaporation of the moisture, distillation and burning of the volatiles before the fixed carbon burns. However, fixed carbon is the solid combustible residue that remains after a wood or bark are heated and the volatile matter is expelled. It is determined by subtracting the percentages of moisture, volatile matter, and ash from the sample. The combustion properties of a given substrate can be found by ultimate and proximate analysis. For determining volatile and ash contents, a TGA instrument (Leco TGA701 Thermogravimetric Analyzer) was utulized according to the ASTM D 5142 protocol. The moisture content determined at 105 °C, ash at 750 °C, volatiles at 950 °C in this experimental process. The heat values were determined by a calorimetry bomb instrument (Leco AC–500). At the end of the process, the energy levels of samples were found in calorific value (Kcal/Kg). The sulfur and carbon content were determined by using a carbon/sulfur analyzer instrument (Leco SC-144) and was determined at 1350 ºC at 3.0 min durations.
Experimental Findings: It has found that selected variables (European Beech components and age groups) have influenced combustion and calorific properties in some level. However, bark was found to be show the lowest fixed carbon ratio of 13.7% in 10 years old samples. The highest volatile matter content of 84.6% was obtained with a 30 years old branch wood sample. Moreover, the highest level of ash content (3.7-9.9%) was found to be with bark samples in all three age groups, regardless of conditions. The measured calorific values looks like very similar in crown wood (4207.8 kcal/kg to 4263.8 kcal/kg) and branch wood samples (4137.8 kcal/kg to 4563.5 kcal/kg) while considerably lower for bark (3776.6 kcal/kg to 4200.7 kcal/kg). It is also important to note that European Beech tree have only showed trace amount of sulfur element (0.03-0.13%) in regardless of maturity and parts of tree.

Open Access Original Research Article

Condensation Reactions of Methyl Derivatives of Quinoxaline-1,4-Dioxide with 4,4'-Biphenyl Carboxaldehyde

Mohamad Alkhudari

Asian Journal of Chemical Sciences, Page 15-21
DOI: 10.9734/ajocs/2021/v10i119083

Aims: To synthesis new compounds via condensation reactions between 2-methyl quinoxaline-1,4-dioxide derivatives 4,4'-biphenyl carboxaldehyde.

Methodology: The Quinoxalines derivatives were prepared from 2-nitroaniline derivatives using the Beirut reaction, and the condensation reaction was carried out at room temperature in absolute methanol. Based on IR and NMR spectroscopic techniques, the structures of all products have been suggested. For their synthesis, suitable mechanisms have been suggested.

Results: In this work, condensation reactions involving 2-methyl quinoxaline-1,4-dioxide derivatives and 4,4'-biphenyl carboxaldehyde were performed.

Conclusion: The final compounds, we suppose, have considerable applications in fluorescent and chromophoric activities. In all known solvents, the products were just slightly soluble. Products have been subjected to sulfonation reactions, although with limited success.

Open Access Original Research Article

Manganese-Doped Carbon Dots Via Inner Filter Effect for the Sensitive Detection of Tetracycline in Poultry Meat Samples

Ke Su, Guoqiang Xiang, Yunlong Zhang, Xin Wang, Linhui Wang, Xinrong Jin, Bocong Li, Gao Huang

Asian Journal of Chemical Sciences, Page 38-46
DOI: 10.9734/ajocs/2021/v10i119085

In this study, a rapid and sensitive analytical method has been developed to detect tetracycline hydrochloride (TC) using manganese-doped carbon dots (Mn-CDs) prepared by one-step hydrothermal procedure using 1-(2-pyridinylazo)-2-naohthalenol (PAN) and MnCl2 as precursor reagents. The obtained Mn-CDs showed an ultraviolet emission at 360 nm with an excitation wavelength of 300 nm. TC has a strong characteristic absorption peak at 356 nm, which has a large spectral overlap with the emission band of the Mn-CDs. The fluorescence intensity (FI) of Mn-CDs at 360 nm is linearly quenched within the TC concentration range of 0.1-200 µM. The developed assay for the detection of TC was based on an inner filter effect (IFE) mechanism and is rapid, sensitive, and was successfully applied for the determination of TC in different poultry meat samples with satisfactory results.

Open Access Review Article

Agricultural Residues as an Alternative Source of Fibre for the Production of Paper in Kenya-A Review

John Odhiambo Otieno, Treezer Nelly Okumu, Morelly Adalla, Fredrick Ogutu, Boniface Oure

Asian Journal of Chemical Sciences, Page 22-37
DOI: 10.9734/ajocs/2021/v10i119084

The pulp and paper industry is primarily dependent on fibrous wood for pulp and paper production. However, this over-dependence on fibrous wood poses serious environmental challenges such as the diminishing of the fibrous wood stocks, deforestation, emission of greenhouse gases, and global warming. Therefore, to mitigate these environmental challenges associated with its utilization for paper and pulp production, other sustainable raw material sources can also be considered for the production of paper and pulp. There are enormous benefits associated with the utilization of non-wood fibres as an alternative and sustainable raw materials source for the production of paper and pulp. These benefits have in the recent past prompted millers in China, India, Brazil, and the USA to consider the utilization of non-wood fibres in paper and pulp production.

In Kenya, the pulp and paper industry is very much dependent on fibrous wood for production and the industry is yet to fully embrace the utilization of nonwood fibres for paper and pulp production. Further, the dependence on fibrous wood has contributed significantly to the decline of paper pulp and paper production, deforestation, and rise in paper importations due to insufficient raw material supplies. The importation of paper and pulp products has further led to the collapse of the paper industry in Kenya. The sector stands a chance of revival and vibrancy through the utilization of the abundant agricultural residues and feedstocks lying in the agricultural fields across the country. Similar experiences elsewhere have proved that the abundance of agricultural waste can be utilized for the production of paper and pulp due to their excellent fibre content for specialty papers, and easy pulpability. The agricultural residues are therefore considered a quintessential alternative and sustainable source of raw materials for the pulp and paper industry. Moreover, their utilization will mitigate environmental impacts such as deforestation, climate change, and pollution .