Extractive Content Research Articles

Preliminary Physical and Chemical Characterization of By-Products from Cuban Coffee Production

Coffee is one of the most consumed beverages worldwide. Its production generates a large amount of waste, and its use is of vital importance to prevent it from becoming a source of environmental pollution. Cuba is a country with a well-known coffee-growing tradition. Although coffee production has decreased, it is vitally important to use the waste generated in these productions to reduce environmental pollution. To know the possible use or application of coffee waste, it is necessary to know its composition. In this article, three Cuban Arabica coffee wastes (husk, parchment and spent coffee grounds) were characterized using chemical, physical and physicochemical methods. In the characterization of these wastes, SEM and EDX were used to determine their microscopic form and chemical composition. The Chesson–Datta method, ATR and TGA were used to determine whether these materials were lignocellulosic. Ash, pH and density of the waste were determined as characterization methods. The extractive content was determined and a phytochemical screening was performed to determine the groups of the secondary metabolites present.

Investigating the physical characteristics and antibacterial properties of the cork back from Quercus variabilis

This study presents for the first time results on structure feature, basic physical properties, torrefaction treatment, adsorption property, component content and antimicrobial properties of the cork back from Quercus variabilis. The cork back consisted of numerous white stone cell bundles with a dense and firm texture and irregularly shaped cells exhibiting considerable deformation and wrinkles. The cork back had the average density of 0.37 g/cm3, average hardness of 91.60 HA and the average thickness was 31.44 % of the total cork thickness. The average colorimetric parameters values of L*, a*, and b* of the cork back were 21.92, 2.34, and 6.42, respectively. Increasing torrefaction temperature increased the quality loss of the cork back, decreased energy yield and volatile matter content, and increased ash and fixed carbon content. With the elevation of fixed carbon, the higher calorific value of the cork back also increased. Following high-temperature torrefaction at 300 °C, the higher calorific value of cork back was 24.00 MJ/kg which increased by 30.29 % compared to untreated cork back. The cork back powder had significant adsorption performance for methylene blue and the maximum adsorption capacity could reach 511.61 mg/g. Compared with cork，the cork back had a high content of lignin and polysaccharides, with a suberin content of only 4.07 %. The total extractives content in cork back was 7.49 %. The water extractives of the cork back exhibited the most significant inhibitory effect on Escherichia coli, with the lowest inhibitory concentration recorded at 2 mg/mL. This research offers essential data for the processing and utilization of the cork back, which contributes to enhance the utilizing efficiency of cork resources.

Valorization of Pineapple Core Waste for Sequential Extraction of Phenolic Compounds and Carotenoids: Optimization Through Ultrasound-Assisted Method and Box–Behnken Design

AbstractIn this study, a pioneering cascade method involving ultrasound-assisted extraction (UAE) and Box–Behnken Design (BBD) was optimized to valorize pineapple core waste by the sequential extraction of, firstly phenolic compounds and, secondly, carotenoids. The effectiveness of the extraction was evaluated based on total polyphenol content (TPC) and antioxidant activity using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Characterization of the carotenoids was performed using high-performance liquid chromatography with a diode array detector (HPLC–DAD). The initial characterization of dry pineapple core (DPC) samples revealed their nutritional composition, including protein, lipid, and carbohydrate weight percentages of 1.20 ± 0.05%, 5.3 ± 0.4%, and 88.6 ± 0.5%, respectively. The high extractives content (40.0 ± 4.5%) suggests a substantial presence of phenolic compounds, making the pineapple core a valuable source of natural antioxidants. The optimal UAE conditions for phenolic compound extraction were 70% amplitude, 5 min extraction time, and 2 cycles, yielding an antioxidant extract rich in phenolic compounds with a desirability value of 81.2%. Therefore, DPC was considered a valuable source of natural antioxidants. The extraction of β-carotene also showed promising results with optimal UAE conditions of 20% amplitude, 3 min extraction time, and 2 cycles. This research promotes the sustainable use of pineapple waste and demonstrates the potential to obtain valuable additives for the food, pharmaceutical, and cosmetic industries, encouraging a more circular and efficient use of resources in the pineapple processing industry.

Variability of the chemical composition of Dendrocalamus giganteus in relation to growth stage

Bamboo is a renewable bioresource with extensive applications, from construction to textiles, and is essential for bioenergy and eco-friendly practices. Despite its potential use in biorefineries, the utilization of abundant species like Dendrocalamus giganteus is hindered by a lack of comprehensive knowledge regarding its chemical composition at various growth stages. In this study, we addressed this gap by quantifying the holocellulose, lignin and extractive contents of D. giganteus from the tropical forests of Bangladesh. We examined the composition across different ages and heights, assessing the solubility of holocellulose, lignin and extractive contents, with a view to enhance the use of D. giganteus in biorefinery industries. We analyzed chemical composition and assessed the solubility using both hot and cold water, as well as conducting 1 % NaOH (caustic soda) solubility tests following the TAPPI (Technical Association of the Pulp and Paper Industry) standards. The holocellulose, lignin, and extractive content increased with the increase age of the bamboo. These components also increased with increasing height, regardless of age. The solubility in water and NaOH, on the other hand, decreased with the increasing age and height positions. The top of 4-year-old bamboo exhibited the highest levels of holocellulose (70.2 %), lignin (29.7 %), and extractive components (6.9 %), but the lowest solubilities in hot water (6.18 %), cold water (3.58 %) and caustic soda (22.48 %). These findings suggest that D. giganteus has potential applications in specific industries, such as pulp and paper, nanocellulose, bioethanol, biochemicals and bio-based composites.

Insights about the use wood waste from the neotropical Amazonian for the generation of renewable energy

The abundance and availability of wood waste in the Amazon region pose a great challenge in terms of their use, such as to generate clean and renewable energy. The use of blends of the most different species constitutes a challenge in view of the energetic characteristics that are unknown for the replacement of fossil fuels. Thus, the objective of this study was to investigate the energy potential of wood waste from Amazonian species (Dinizia excelsa and from Manilkara elata, commonly used as lumber) as a way to support the generation of clean and sustainable energy. The wood waste of two Amazonian species were collected during the mechanical processing of logs; the sawdust of Eucalyptus spp. was collected in a biomass company. The contents of total extractives, total lignin, ash, moisture, bulk density, calorific value and energy density were investigated in different blends of residual biomass. The Dinizia excelsa species stood out for presenting higher values of extractives, total lignin, calorific value and energy density. The waste of Amazonian species showed satisfactory characteristics for energy use, which encourages the use of this biomass from wood processing. In addition, forest biomass waste enable the production of various compacted solid fuels, such as pellets and briquettes.

Rapid estimation of wood density and total extractives of two important Dalbergia species using near-infrared (NIR) spectroscopy and multivariate analysis

ABSTRACT Wood density and chemical extractives are important parameters influencing timber quality and utility in wood industry. Several wood properties, particularly mechanical parameters and durability, depend respectively on density and extractive contents. This study aimed to apply the near-infrared (NIR) spectroscopy technique for rapid and accurate estimation of density and extractive contents of Dalbergia latifolia and D. sissoo wood species. The objective was to develop a predictive model for properties, addressing the critical gap in efficient and large-scale assessment techniques for wood industries. Density and extractive contents were determined by conventional and wet chemistry methods. Spectral data of woods were subjected to multivariate analysis to improve the accuracy of calibration models and performance was assessed using coefficient of determination (R²) and root mean square error of prediction. The optimised models exhibited good predictive accuracy with high R²of 0.85 and 0.82 for density and extractive contents respectively. Spectral patterns correlating density and extractive variations identified provided valuable insights into the chemical composition and density relationship in Dalbergia species. The study thus highlights the potential of this non-invasive analytical approach in assessing the quality parameters, which would facilitate sustainable utilisation and contribute to the advancement of woodworking industries.

Development of Wood-Based functional composites for advanced sensing and energy conversion applications

With the low carbon-driven development of modern intelligent, research towards novel materials is concentrating on the sustainable biomass-based advanced functional composites. The advanced functionalized wood toward sensing, optoelectronic devices, and energy conversion has been contributed to fast electron transport upon temperature or photo stimulus. Fast electron transport has been highly depended on the interfacial adhesion between the functional layer and wood matrix as well as graphitization degree during carbonization, which promote the electronic excitation and jumps. Here, we develop wood-based functional composites for advanced fire warning and energy conversion by loading metal–insulator transition (MIT) function factor (Ti3O5) onto different woods via liquid crosslinkers, and systematically establish the interfacial adhesion-carbonization-electron transport processes and their relationships on the sensing and photothermal conversion properties. Firstly, balsa with high porosity (pore diameter ≈50 μm), low density (0.16 g/cm3) and extractives content (total extractives content 16.27 %) facilitates crosslinker penetration due to the more holding space and lower nonpolar components. A favorable permeation can promote better interfacial adhesion, and the formation of a continuous conductive network of char-layers during carbonization. Secondly, the crosslinker (chitosan) with excellent adhesion (1 level) and char-forming ability (char residues is 21.7 %), facilitates the formation of a compact network of highly graphitized char-layers (ID/IG=0.81), which increases the electrical conductivity (highest conductivity 5.52 × 10-4 S/m). We found that the most sensitive flame trigger time (0.86 s) for fire warning and the highest evaporation flux (1.63 kg m-2h−1) for desalination can be obtained by using balsa which coupled the chitosan as well as the Ti3O5.

Impact of thermal treatment on the properties of assacú (Hura crepitans L.) and murici (Byrsonima crispa A.Juss.) Amazon woods

Background: White and low-density Amazon woods, such as assacú (Hura crepitans L.) and murici (Byrsonima crispa A.Juss.), have restricted use, given their low physical-mechanical strength and low natural durability. Physicochemical changes caused by heat treatment can improve different quality traits of these woods, such as changing the visual appearance from white to brown tones, improving dimensional stability, moisture control, and resistance to attack from biological organisms. Methods: Assacú and murici wood samples were heat treated (180 and 220°C) for 60 minutes in a muffle kiln. The physical (moisture, mass loss, density, shrinkage, swelling), mechanical (dynamic modulus of elasticity), and chemical (extractives, solubility in hot water, lignin, and holocellulose) properties were evaluated following treatment and compared with those measured before treatment. Results: The heat treatments T2 (180°C) and T3 (220°C) reduced the moisture content; however, the T3 treatment caused a more intense mass loss. For murici wood, this mass loss was 14%. The anisotropy coefficient was reduced for assacú wood by 1.30 and 1.03% for the T2 and T3 treatments, respectively, improving the dimensional stability of this wood. The density and modulus of elasticity were affected by the treatment, thus reducing the strength of the wood. The extractive content of the woods increased by 4.99 and 7.49% for sampled of assacú and murici, respectively, that were treated at 220°C. For the primary metabolites, holocellulose and lignin, degradation of these compounds occurred due to the decrease in their concentrations. The linear analysis of the studied variables indicated a high correlation between the physical properties and the chemical components of the woods (e.g., anisotropy coefficient x lignin and holocellulose x apparent density, r > 0.95). Conclusions: The heat treatment of Amazon woods directly influenced their physical-mechanical and chemical properties. In general, the higher temperature treatment caused the greatest changes in the studied species, and the exposure to heat caused noticeable changes in their colour. Heat treatment is a useful process for the forestry sector since heat-treated wood can be used to manufacture high-value-added products, such as fine furniture, residential floors, musical instruments, and non-structural components.

Chemical changes in thermally modified, acetylated and melamine formaldehyde resin impregnated beech wood

Abstract Wood modification (by thermal or chemical treatment) helps to improve the dimensional stability of wood and enhance its resistance to biological agents. Beech wood is non-durable and exposure in exterior settings dramatically shortens its service life. To determine the full potential of beech wood for advanced applications, a better understanding of the chemical changes induced by modification is needed. Two chemical treatments (acetylation and melamine formaldehyde resin impregnation) and three thermal treatments (heating to 180, 200 and 220 °C) were performed on beech wood. The modification effect was examined based on (i) molecular changes in functional groups by Fourier-transform infrared spectroscopy (ATR-FTIR); (ii) extractive content; and (iii) pH changes. Moreover, the explanation of these changes was supported by the FTIR-analysis of isolated main wood components (cellulose, holocellulose and lignin) from the modified wood. The high temperatures applied to samples during thermal modification promoted the deacetylation and degradation of hemicelluloses. Hemicelluloses were targeted also by acetic anhydride and melamine resin, the bonding of which was confirmed by FTIR analysis. The formation of fewer methylene bridges affected the properties of the melamine network. This observation suggests the need to determine optimal curing conditions in future research, to reduce melamine-wood hydrophilicity.

Quercus robur wood veneer with pronounced natural color uniformity and stability by regulating the content of phenolic extractives

Wood is recognized as a promising raw material for house furnishings due to its good mechanical properties, relatively low density and weight and biodegradability. However, the natural color difference of wood veneer always induces value degradation. Therefore, accurate color regulation plays a pivotal role in producing high-value wood-based composites. In this study, a Quercus robur wood exhibiting a pronounced color variation was treated by an alkaline hydrogen peroxide (H2O2) homogenization process to regulate the content of phenolic extractives, and ferric chloride (FeCl3)-induced color modification to optimize the color. In order to minimize the chromatic disparity of the veneer, it simultaneously restores its initial hue and thus enhances its value. The color difference values of natural untreated Quercus robur veneer and homogenized toned veneer were assessed by using color testing based on the CIEL*a*b* 1976 system. The results demonstrated that the levels of lignin, hemicelluloses, and extractives in the toned veneers subjected to homogenization pretreatment exhibited varying degrees of reduction, along with a decrease in their affinity for iron ions. By assessing the colorfastness of homogenized, toned veneer through testing, the water and light resistance of the homogenized pretreated veneer is significantly superior to that of Quercus robur treated exclusively with iron salts. A higher level of color uniformity in the homogenized pretreated toned veneers, with the toned veneers treated with 0.16 mol/L iron salt exhibiting the closest resemblance to natural Quercus robur wood. This study not only reveals a novel methodology for chemically modifying the hue of wooden surfaces to achieve natural color uniformity but also presents a sustainable and facile approach to promote the high value-added utilization of wood.

Charring of and Chemical Changes in Historical Wood under Thermal Loading

Research in historical timber assessment is hindered by the limited availability of samples, yet understanding the fire resistance of historic wood is crucial for preservation efforts. There is an opinion that historic wood behaves similarly to contemporary wood in terms of fire resistance. The aim of this paper is to observe the rate of charring of historical pine wood during the experiment, the color changes in the sample that occurred due to thermal loading, and the changes in the chemical composition of pine wood. Test samples made from historic pine wood were loaded with a 50 kW∙m−2 radiation panel for 60 min. The charring process was faster at the beginning of the charred layer formation. The charring rate at the beginning of the test at a depth of 10 mm from the exposed side reached values from 1.28 mm∙min−1 to 3.16 mm∙min−1. At a depth of 30 mm from the exposed side, the individual charring rates approached a value of 1 mm∙min−1 (0.99 mm∙min−1 to 1.08 mm∙min−1). Observations during medium-scale testing revealed distinct layers forming on the exposed side: a charred layer, charring base, pyrolysis layer, and intact wood. The chemical composition of the wood changed under the influence of the thermal load. The relative contents of extractives and holocellulose decreased with the increasing temperature while the lignin content increased. The highest value of combustion heat was measured in the charred layer of the sample. Correlation analysis demonstrated a negative relationship between the combustion heat and holocellulose, while a positive correlation was found with the lignin content. Chemical changes were also monitored using the FTIR method. These findings provide valuable insights into the behavior of historic pine wood under thermal loading, which is essential for understanding and preserving historical structures.

Chemical Composition as the Indicator of Thermally Treated Pine (Pinus sylvestris L.) Wood Colour

This study aimed to determine the influence of increased temperature on the mass loss, chemical composition, and colour of pine wood because of the lack of such information. The colour was measured on samples of wood, extracted sawdust, holocellulose, and lignin isolated from the extracted sawdust of pine heartwood and sapwood. A wood sample labelled 20 °C was considered as wood with the original composition. Subsequently, we verified the measured values with the proposed mixing colour model. Pine heartwood and sapwood samples were thermally treated at temperatures of 100, 150, 200, 220, 240, and 260 °C for 1, 3, and 5 h. It was found that sapwood degraded faster than heartwood. The thermal treatment of wood increases lignin content and decreases holocellulose content, especially at 260 °C. The maximum extractive content of 3.60% was at 1 h and a temperature of 260 °C for both parts of the wood. Lightness values decreased with increasing temperature and time of treatment. The coordinate a* of heartwood showed a positive slope until one hour of treatment duration and a temperature of 240 °C. Then, it decreased for the subsequent duration of treatment. The same course was shown for the coordinate b* of sapwood at a temperature of 200 °C. The proposed model of mixing colours proved that changes in both parts of a wood-extracted substance, holocellulose, and lignin content, were responsible for the changing colour of extracted wood.

Origin-specific differences in the durability of black locust (Robinia pseudoacacia) wood against wood-destroying basidiomycetes

Global climate change is accompanied by a change in tree composition in many regions. In Europe, the distribution areas of many species are expanding towards the north so that, among others, black locust (Robinia pseudoacacia), which is native to the USA and has long been established in south-eastern Europe, is also becoming increasingly important in central and northern Europe. Many other tree species are known to have different properties between their original and new locations, including the biological durability of the wood. Hence, the resistance of black locust wood against decay fungi was studied concerning origin-specific differences. Wood was sampled from seven different origins in Europe and original habitats in the United States. Fungal incubation experiments were conducted, wood extractives were analysed, and different anatomical characteristics were quantified such as ring width, vessel size distribution and the presence of tyloses. In addition to differences in durability between juvenile and mature wood, origin-specific differences within the mature heartwood were attributed to extractive contents and the percentages of earlywood vessels containing tyloses. Based on parameters that contributed at least 20% to mass loss, susceptibility to fungal decay was modelled with multiple regressions.

Ethno Medicinal, Phyto-Chemical and Physico-chemical Characterization of Selected Endangered Medicinal Plants of Indravati National Park, Bijapur, Chhattisgarh, India

Medicinal plants are beneficial for curing several ailments among traditional healers, indigenous people, local practitioners and forest dwellers. If harnessed, traditional knowledge of the ethnomedicinal plants can play a pivotal role in drug discovery and development. In many cases a single medicinal plant can be of multiple uses also, different plant parts of the same plant can be utilized for more than one disease condition. The Ethno-botanical, Phytochemical and physico-chemical characterization of five selected medicinal plants viz., Nyctanthes arbor – tristis, Andrographis paniculata, Cissus quadragularis, Plumbago zeylania and Costus specious is an essence and has been carried out to assess bioactive potential and to establish traditional belief in the light of scientific interpretation. Fresh leaves were collected from Indravati National Park, Bijapur, Chhattisgarh, India, dried and powdered for phytochemical and Proximate, ultimate, and compositional analysis. Study revealed that the highest concentration of Ash Content (18.513%), Moisture Content (8.56%), Carbon content (48.77%), Hydrogen Content (24.490%), Nitrogen Content (23.860%) was observed to occur in Plumbago zeylanica leaf than other experimental plants. In Cissus quadrangularis, the percentage composition of fat content (0.230%), extractive content (1.05%), Lignin Content (5.53%) was higher than others. Fat content (0.230%), Moisture Content (8.56%), Vit. C content (64.63%) and Oxygen contents (36.655 %) were observed to be higher in Nyctanthes arbor-tristis leaf than others. The concentrations of Crude Fibre (14.49 %), Moisture Content (8.56%), Protein content (12.16%), Carbon content (75.66 %), Cellulose content (47.63 %) were observed to be highest in Costus speciosus species than others. Carbon content (48.77%) and Hydrogen Content (24.490%) were higher in Andrographis paniculata than in others.

Effect of ethanolic plant extractives on cephalic neuroendocrine system of BmNPV inoculated 5th instar larvae of Bombyx mori L. (Lepidoptera, Bombycidae)

In this research 3000, 5000 and 8000ppm concentration of ethanolic extractives of leaves of Eupatorium odaratum, Hyptis suaveolens and fruits of Aegle marmelos were tested on mulberry silkworm fifth instar larvae of PMxCSR2 inoculated with Bombyx mori Nuclear Polyhedrosis Virus (BmNPV). Extractives of A. marmelos, H. suaveolens and E. odaratum showed promising results against BmNPV of silkworm larvae @8000 ppm. Total improvement occurs in the function of neurosecretory cells (NSC), A1 and A2 cells of median neurosecretory cells (MNC) group. Also found that, NCC I and II, corpus cardiacum (CC) lobes and fine branching of NCA I over corpus allatum (CA) showed strongly stained PF positive granules of NSM due to the subsequent treatment of given ethanolic plant extractives which reduced BmNPV infection about (30 - 40%).

THE RELATIONS BETWEEN NON-STRUCTURAL SUBSTANCES, ANNUAL RINGS WIDTH AND LATEWOOD SHARE IN PINUS SYLVESTRIS L. STEM

Extractives and ash contents, share of latewood and annual rings width were analyzed in wood at different heights and different zones of the Pinus sylvestris L. stem cross-section. Additionally, the high performance liquid chromatography (HPLC) with a conductometric detector was applied to determine the sulphate (SO42-) and hydrogen phosphate (HPO42-) anions concentrations in wood and bark of Pinus sylvestris L. stem. In this paper, based on the results it was observed, that generally extractives content increased in the direction from sapwood perimeter to middle heartwood and pith adjacent heartwood zone. Moreover, the results showed that the greater share of latewood in annual rings the lower ash and extractives contents in the wood, but the higher sulphate (SO42-) and hydrogen phosphate (HPO42-) anions concentration. The sulphate (SO42-) and hydrogen phosphate (HPO42-) anions concentrations in the bark of the Pinus sylvestris L. stem were higher at the top than at the butt-end part.

Effect of accelerated extraction and sonication on the antioxidant capacity of wood and bark extracts of wet-hearted silver fir (Abies alba Mill.)

The aim of this study was to compare the antioxidant capacity of hydrophilic extracts of different tissues of wet-hearted silver fir (Abies alba Mill.) logs. Wet heart is a wood defect of silver fir and lowers the value of wood. The exploitation of extractives could increase utilization and financial returns. The bark, sapwood, heartwood and knotwood were investigated by using two green extraction methods: ultrasound assisted extraction (US) and accelerated solvent extraction (ASE), with aqueous ethanol as solvent. Total extractive content (TEC), total polyphenol content (TPC) and antioxidant capacities (FRAP, DPPH, ABTS) from the extracts were determined and compared. The highest contents of total hydrophilic extractives were measured in knotwood (23.07%, ASE) and bark (10.31%, ASE), and the lowest values were determined for sapwood (2.00%, ASE) and heartwood (3.56%, ASE). The ASE method resulted in significantly higher TPC (0.65–10.58%) than the US (0.46–9.19%) method. Nevertheless, the simplicity of instrumentation and costs can make US also a potential candidate for future extraction and utilization. The highest antioxidant capacities were measured in knotwood (FRAP: 159.75 mg AAE/g, ABTS: 316.15 mg TE/g, DPPH: 189.23 mg TE/g) and bark (FRAP: 159.75 mg AAE/g, ABTS: 126.81 mg TE/g, DPPH: 74.52 mg TE/ g) extracts, prepared with ASE, which complements well the existing literature data on silver fir extractives. The knotwood and bark of wet-hearted silver fir is an abundant source of antioxidant polyphenols, whereas sapwood and heartwood are poor in these extractives and potentially unsuitable for the valorization by the extraction of natural antioxidants.

Characterization of natural cellulosic fiber extracted from Grewia ferruginea plant stem

The use of natural fibers as reinforcement in polymer composites has gained significant attention due to their eco-friendly, and biodegradability. This study aims to extract and characterize the natural cellulosic fibers from the Grewia ferruginea stem. The fibers were extracted from plant stems using sodium hydroxide and analyzed using Fourier Transform infrared spectroscopy (FTIR) to determine chemical bonds on the fiber and functional group and Thermos-gravimetric analysis (TGA) was used to determine the thermal stability and degradation temperature of the fiber. The crystalline properties of extracted fibers were characterized by x-ray diffraction and surface morphology was characterized by Scanning electron microscopy. The chemical composition of the fibers, including cellulose, hemicellulose, lignin, moisture, extractive content, and fiber linear density, was evaluated. Tensile, thermal, and FTIR studies were conducted to assess the performance properties of the extracted fiber. The analysis revealed that the Grewia ferruginea fibers contain cellulose (60.4–72.6 wt%), hemicellulose (18.5 ± 3.1 %), and lignin (13.55 ± 2.75 %). The extracted fibers have a crystallinity index of 48.76 % and crystallite size of 5.14 nm. The fiber exhibited tenacity, breaking elongation, and Young's modulus values of (52.3 ± 6.5 cN/tex), (3.6 ± 1.8 %), and 43.5 ± 2.3 GPa, respectively. FTIR studies confirmed the presence of biopolymers in the Grewia ferruginea fiber. Additionally, the fibers demonstrated thermal stability up to 275 °C based on thermogravimetric analysis. These findings suggest that the extracted natural cellulosic Grewia ferruginea fiber has the potential to be used as a sustainable reinforcement material in polymeric composites.

Industrial Two-Phase Olive Pomace Slurry-Derived Hydrochar Fuel for Energy Applications.

The present study aims to resolve the existing research gaps on olive pomace (OP) hydrochars application as a fuel by evaluating its molecular structures (FTIR and solid NMR analysis), identifying influential characteristics (Pearson correlation analysis), process optimization (response surface methodology), slagging-fouling risks (empirical indices), and combustion performance (TG-DSC analysis). The response surfaces plot for hydrothermal carbonization (HTC) of OP slurry performed in a pressure reactor under varied temperatures (180-250 °C) and residence times (2-30 min) revealed 250 °C for 30 min to be optimal conditions for producing hydrochar fuel with a higher heating value (32.20 MJ·Kg-1) and energy densification ratio (1.40). However, in terms of process efficiency and cost-effectiveness, the optimal HTC conditions for producing the hydrochar with the highest energy yield of 87.9% were 202.7 °C and 2.0 min. The molecular structure of hydrochar was mainly comprised of aromatic rings with methyl groups, alpha-C atoms of esters, and ether bond linkages of lignin fractions. The slagging and fouling risks of hydrochars were comparatively lower than those of raw OP, as indicated by low slagging and fouling indices. The Pearson correlation analysis emphasized that the enrichment of acid-insoluble lignin and extractive contents, carbon densification, and reduced ash content were the main pivotal factors for hydrochar to exhibit better biofuel characteristics for energy applications.

Kinetics Comparison of Solid-State Polycondensation and Melt Postpolycondensation for Polyamide 6 with Controllable Extractive Content

Kinetics Comparison of Solid-State Polycondensation and Melt Postpolycondensation for Polyamide 6 with Controllable Extractive Content