Application of K-impregnated staghorn coral as catalyst in the transesterification of waste cooking oil

This work focuses on the catalytic potential of K-impregnated staghorn coral as a catalyst in methyl esters production via methanolysis of waste cooking oil (WCO). The prepared catalyst was analyzed by Hammett indicators, XRF, Brunauer-Emmett-Teller (BET)-N2 adsorption method, ATR-FTIR, TGA, XRD and SEM to determine its physicochemical properties. ATR-FTIR and XRD results confirmed the formation of K2O species upon KOH impregnation, thus, resulting in good catalytic activity. Reaction parameters such as methanol to oil ratio, reaction time and amount of catalyst were evaluated to find out the best conditions for the transesterification process. About 89.51 ± 4.78 % of biodiesel contents were obtained under the optimum conditions

Determination of total phenol, condensed tannin and flavonoid contents and antioxidant activity of Uncaria gambirextracts

Uncaria  gambir,  a  well  known  Southeast  Asia  plant  have  been  previously used as an alternative medicine for treatment such as diarrheal, sore throat and spongy  gums.  Due  to  its  useful  properties,  in  this  study  we  have  analysed  the total  phenol,  condensed  tannin,  flavonoid  content  and  antioxidant  activity  of Uncaria  gambir in  three  different  solvent  extracts.  Characterization  and quantification analysis using Fourier Transform Infrared (FTIR) spectroscopy and reverse  phase-high  performance  liquid  chromatography  (RP-HPLC)  has confirmed  that  the  major  chemical  constituents  of  Uncaria  gambir are  mainly catechins.  It  was  revealed  that  the  ethyl  acetate  gambir  extract  gives  the highest  catechin  content  and  antioxidant  activity  compared  with  other  solvent extracts.Key words: Uncaria gambir, antioxidant activity, condensed tannin, flavonoid

Green Composites Made of Bamboo Fabric and Poly (Lactic) Acid for Packaging Applications—A Review

Petroleum based thermoplastics are widely used in a range of applications, particularly in packaging. However, their usage has resulted in soaring pollutant emissions. Thus, researchers have been driven to seek environmentally friendly alternative packaging materials which are recyclable as well as biodegradable. Due to the excellent mechanical properties of natural fibres, they have been extensively used to reinforce biopolymers to produce biodegradable composites. A detailed understanding of the properties of such composite materials is vital for assessing their applicability to various products. The present review discusses several functional properties related to packaging applications in order to explore the potential of bamboo fibre fabric-poly (lactic) acid composites for packaging applications. Physical properties, heat deflection temperature, impact resistance, recyclability and biodegradability are important functional properties of packaging materials. In this review, we will also comprehensively discuss the chronological events and applications of natural fibre biopolymer composites

Green Composites Made of Bamboo Fabric and Poly (Lactic) Acid for Packaging Applications—A Review

Petroleum based thermoplastics are widely used in a range of applications, particularly in packaging. However, their usage has resulted in soaring pollutant emissions. Thus, researchers have been driven to seek environmentally friendly alternative packaging materials which are recyclable as well as biodegradable. Due to the excellent mechanical properties of natural fibres, they have been extensively used to reinforce biopolymers to produce biodegradable composites. A detailed understanding of the properties of such composite materials is vital for assessing their applicability to various products. The present review discusses several functional properties related to packaging applications in order to explore the potential of bamboo fibre fabric-poly (lactic) acid composites for packaging applications. Physical properties, heat deflection temperature, impact resistance, recyclability and biodegradability are important functional properties of packaging materials. In this review, we will also comprehensively discuss the chronological events and applications of natural fibre biopolymer composites

FTIR-based metabolomics for characterization of antioxidant activity of different parts of Sesbania grandiflora plant

Sesbania grandiflora, one of the flowering plants with great potential as a source of natural antioxidants because it contains chemicals such as tannin, phenolics, and flavonoids. However, there has been no extensive investigation on the antioxidant activity of isolated from different parts of this plant. This study aims to investigate the correlation between antioxidant activity and secondary metabolites extracted from three different parts (leaves, stem barks, and roots) of S. grandiflora plant using Fourier-transform infrared spectroscopy (FTIR) based metabolomics approach. The FTIR is a very useful technique for identifying the functional groups present in the mixtures, while antioxidant assay provides the base to select the part of the plant as the most potential source of antioxidant. The antioxidant properties were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), and potassium ferricyanide reduction method. The multivariate data - analyses using Principal Component Analysis (PCA) and Partial Least Square (PLS) were conducted to compare the distribution of metabolites extracted from different parts of the S. grandiflora plant investigated. The PLS was performed to evaluate the relationship between the components of the extracts obtained from different parts of the plant and their antioxidant activities. The results exhibited that antioxidant activities of the extract of the stem barks, and roots are higher than that of the extract of the leaves. Also, the PLS model indicated that the functional group absorption data were significantly correlated with the IC50 values of antioxidant activity. Subsequently, based on the results of PLS analysis displayed that C=C, C=O, and along with C-O functional groups are proposed as the main contributors to the antioxidant activity of the extracts tested. The extracts of different parts were grouped using PCA analysis with a total of principal components (PC) of 94%

Exploring the effect of cellulose nanowhiskers isolated from oil palm biomass on polylactic acid properties

In this work, polylactic acid (PLA) reinforced cellulose nanowhiskers (CNW) were prepared through solution casting technique. The CNW was first isolated from oil palm empty fruit bunch microcrystalline cellulose (OPEFB-MCC) by using 64% H2SO4 and was designated as CNW-S. The optical microscopy revealed that the large particle of OPEFB-MCC has been broken down by the hydrolysis treatment. The atomic force microscopy confirmed that the CNW-S obtained is in nanoscale dimension and appeared in individual rod-like character. The produced CNW-S was then incorporated with PLA at 1, 3, and 5 parts per hundred (phr) resins for the PLA-CNW-S nanocomposite production. The synthesized nanocomposites were then characterized by a mean of tensile properties and thermal stability. Interestingly to note that incorporating of 3 phr/CNW-S in PLA improved the tensile strength by 61%. Also, CNW-S loading showed a positive impact on the Young’s modulus of PLA. The elongation at break (Eb) of nanocomposites, however, decreased with the addition of CNW-S. Field emission scanning electron microscopy and transmission electron microscopy revealed that the CNW-S dispersed well in PLA at lower filler loading before it started to agglomerate at higher CNW-S loading (5 phr). The DSC analysis of the nanocomposites obtained showed that Tg,Tcc and Tm values of PLA were improved with CNW-S loading. The TGA analysis however, revealed that incopreated CNW-S in PLA effect the thermal stability (T10,T50 and Tmax) of nanocomposite, where it decrease linearly with CNW-S loading

Development of immobilized microcrystalline cellulose as an effective adsorbent for methylene blue dye removal

This article presents the work done on the utilization of microcrystalline cellulose (MCC) extracted from oil palm fronds (OPF) as a renewable and novel adsorbent. Poly (vinyl chloride) (PVC) and epoxidized natural rubber-50 (ENR-50) were used for the immobilization of MCC/ENR/PVC on the glass substrate to evaluate in a fabricated glass cell. It was revealed that the adsorption of MB dye with immobilized OPF MCC gives a maximum adsorption capacity, qmax of 12.85 mg g−1 in Langmuir isotherm. It was proposed that monolayer adsorption occurred at the homogenous surface of the immobilized OPF MCC. Besides, the adsorption process dominant physisorption that was verified by the Gibbs free energy of adsorption (ΔG°). Meanwhile, the adsorption kinetic studies revealed the coefficient of determination in Elovich model was fitted moderately resulted in physisorption, even though the experimental data was corresponded to pseudo-second order kinetic model. Additionally, the intra-particle effect was observed to be more significant at high concentration, which was shown in the increment of the rate constant with initial dye concentration. This study indicates that immobilized OPF MCC has the potential as a green adsorbent and offered the unique advantage of convenient use. Keywords: Adsorbent, Methylene blue, Microcrystalline cellulose, Oil palm frond

Potentials of Canarium schweinfurthii seed shell as a novel precursor for CH3COOK activated carbon: statistical optimization, equilibrium and kinetic studies

Abstract The possibility of utilizing Canarium schweinfurthii seed shell (CSSS) as a precursor to optimally produce activated carbon was harnessed by physico-chemical activation. Carbon (IV) oxide (CO2) and potassium acetate (CH3COOK) were employed as physical and chemical activating agents, respectively. Its ability as an effective adsorbent was tested on aqueous solution by removing 2,4,6-trichlorophenol (2,4,6-TCP). Central composite design was employed for the optimization giving rise to activation temperature of 670 °C, activation time of 100 min and impregnation ratio of 2.43. The optimal adsorbent (CSSS-AC) can be classified as mesoporous with surface area of 925.77 m2 g−1 and maximum adsorption capacity of 247.23 mg g−1. Higher amount of 2,4,6-TCP was removed at low pH with Freundlich and pseudo-second-order models found to be the most appropriate isotherm and kinetic model, respectively, in describing the adsorption process. The results reveal that C. schweinfurthii seed shell could be recommended as a promising novel precursor for producing activated carbons with high surface area and potentially desirable 2,4,6-TCP removal capacity, using CH3COOK as an effective activating agent

The effect of Tinospora crispa extracts as a natural mild steel corrosion inhibitor in 1 M HCl solution

The potential of Tinospora crispa extracts as a corrosion inhibitor of mild steel in 1 M HCl was determined using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy methods (EIS). Maximum inhibition was attained at the concentration of 800 and 1000 ppm for TCDW (T. crispa water extract) and TCAW (T. crispa acetone–water extract). The inhibition efficiencies of T. crispa extracts obtained from the impedance and polarization measurements were in good agreement where the maximum inhibition is around 70–80%. Potentiodynamic polarization measurement studies revealed that T. crispa extracts behave predominantly as an anodic inhibitor. The adsorption of T. crispa extracts was found to follow Langmuir’s adsorption model

Physicochemical characterization of alkaline and ethanol organosolv lignins from oil palm (Elaeis guineensis) fronds as phenol substitutes for green material applications

International audienceIn the present work, lignin isolation and physicochemical features from oil palm fronds (OPF) black liquor using Kraft, soda and organosolv pulping have been studied. The characterization of lignin samples by means of FTIR, H-1 and C-13 NMR has shown that different types of hydroxyl functional groups were obtained from different delignification processes. It was revealed that the lignin samples contained substantial amounts of non-condensed guaiacyl and syringyl unit with fewer p-hydroxyphenyl units. The GSH molar ratio of Kraft, soda and organosolv lignin was assigned to 26:51:21,21:49:30 and 23:67:10, respectively, upon quantification. The significant differences in the physicochemical features of the lignin isolated with alkali and organosolv treatments may be of great interest as a promising alternative for its revalorization