ABSTRACT
Surface-active softening agents, such as Fatliquors, have a significant impact on the leather industry as they enhance the physicochemical properties of leather. This study focuses on analyzing the synthesis, properties, characterization, and sulfonation of Swietenia mahagoni seed oil to determine its potential as a fatliquoring agent for leather. An investigation was conducted to verify the alteration of Swietenia mahagoni oil through the analysis of its properties before and after the sulfonation process. A scientific analysis was carried on the oil using GC-FID, revealing the presence of various unsaturated fatty acids such as linoleic, linolenic, oleic, palmitic, and arachidic acids. This demonstrates the sulfonating capability of this sky fruit seed oil. A fatliquor was created by sulfonating the oil, and the sulfonation was verified through Fourier Transform Infrared Spectroscopy (FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectra. The prominent peak observed at 1209 cm-1 in the FTIR spectra indicated the stretching of S=O in both sulfate and sulfonate groups. The newly formed protons (H-C-S or H-C-O) showed signals between δ 4.09 and 4.29 ppm in the 1H NMR spectra, confirming the sulfonation of the fatliquor that was prepared. Moreover, the change in the melting point of sulfonated Mahogany oil from 40.8 °C to 48.1 °C suggests increased saturation levels. The fatliquor's emulsion stability was found to be at a satisfactory level. After conducting tests on the treated leather, the physical strength and morphological structure was analyzed using Field Emission Scanning Electron Microscopy (FE-SEM), the fatliquor improved the lubrication and strengthened the fibrous network structure of the leather, composed of thin and tight collagen fibers. The BOD5/COD ratio of the effluent from the experimental trial was determined to be 0.52, suggesting that the fatliquor developed is a biodegradable product. Finally, the antifungal capabilities of the fatliquor-treated leather were tested against four different fungus species: Aspergillus niger, Aspergillus flavus, Penicillium notatum, and Candida albicans, and the treated leather sample shown favorable antifungal activity.
ABSTRACT
Utilization of vegetable tannins in leather processing is one of the convenient solutions to protect the environment pollution. Herein, the banana bunch and syrup of banana stem are utilized to prepare an ecofriendly tanning agent. The yield of banana bunch extraction efficiency is found 69.80 %. FT-IR analysis confirmed the presence of condensed type tanning component owing to the bearing of different polyphenolic groups. The content of tannins in extracted banana bunch and stem syrup is 3.13 % and 2.6 %, respectively. The phenolic content in the banana bunch extract is determined to be 1332.37 mg GAE/100g of dried weight and in syrup was 873.92 mg GAE/100g of dried weight. This makes it possible to be used as vegetable tanners. The extracted bunch and syrup are applied to re-tan leather and compared with conventionally used vegetable tanning agent (quebracho) in parallel. Tensile strength, tear strength and elongation percentage for the extracted banana bunch and syrup are obtained at 23.84 N/mm2, 68.26 N/mm, 47.07 %, and 22.97 N/mm2, 68.38 N/mm, 40.70 %, respectively. The softness is found 1.41 for the extracted bunch and 2.01 for the syrup. The grain crack load, distension at grain crack, strength at ball burst, distension at ball burst are 246.86 N, 13.24 mm, 530.77 N, 24.54 mm for banana stem syrup and 338.77 N, 13.42 mm, 460.65 N, 29.08 mm for bunch extract, respectively. The shrinkage temperatures recorded for banana bunch extract, syrup and Quebracho (control trial) tannins tanned leather samples are 76.5 °C, 75 °C and 84 °C subsequently. The flexing endurance of the bunch extract and syrup revealed acceptable values that are less than 4. Moreover, the bunch extract tanned leather shows greater thermal stability and for syrup it is similar with the quebracho tanned leather. All the results are satisfactory compared to the control trial. Finally, tanned leather is evaluated to assess the possibility of the newly developed tannin which proves its efficiency as a potential source of tanning material for the leather industry.
ABSTRACT
In Bangladesh, the annual production of rubber seeds is typically left untapped although the seeds contained a high percentage of oil but underutilized without any value-added utilization. This study aims to evaluate the geographical effect on physicochemical properties, fatty acid composition and the antimicrobial activity of oil extracted from rubber seeds. Seeds were collected from three different regions of Bangladesh and the oil was extracted by the soxhlet method using n-hexane as a solvent. Results demonstrated that the geographical regions have some significant effect on the properties of rubber seed oil (RSO). The physicochemical properties of RSO varied from region to region. For example, the percent of yield, higher heating value, and flash point varied from 50.0 to 50.8 %, 31.8-33.3 kJ/g, and 237-245 °C, respectively. The chemical parameters, such as acid value, iodine value, and hydroxyl value varied from 13.3 to 18.2 mg KOH/g, 132-137 g I2/100g, and 47.7-55.8 mg KOH/g, respectively. Chromatographic analysis showed that RSO mainly contains palmitic, linoleic, linolenic, and stearic acid. Regional variations were also seen in the composition of these fatty acids. Most notably, regardless of the rubber seeds collected from various locations, RSO exhibited inhibitory activity against only gram positive bacteria. The zone of inhibition range for different tested gram positive bacteria was 2.33-11.17 mm irrespective of different RSO samples.
ABSTRACT
Polymers obtained from biomass are a concerning alternative to petro-based polymers because of their low cost of manufacturing, biocompatibility, ecofriendly and biodegradability. Lignin as the second richest and the only polyaromatics bio-polymer in plant which has been most studied for the numerous applications in different fields. But, in the past decade, the exploitation of lignin for the preparation of new smart materials with improved properties has been broadly sought, because lignin valorization plays one of the primary challenging issues of the pulp and paper industry and lignocellulosic biorefinery. Although, well suited chemical structure of lignin comprises of many functional hydrophilic and active groups, such as phenolic hydroxyls, carboxyls and methoxyls, which provides a great potential to be applied in the preparation of biodegradable hydrogels. In this review, lignin hydrogel is covered with preparation strategies, properties and applications. This review reports some important properties, such as mechanical, adhesive, self-healing, conductive, antibacterial and antifreezing properties were then discussed. Furthermore, herein also reviewed the current applications of lignin hydrogel, including dye adsorption, smart materials for stimuli sensitive, wearable electronics for biomedical applications and flexible supercapacitors. Overall, this review covers recent progresses regarding lignin-based hydrogel and constitutes a timely review of this promising material.
