Degradation Temperature Research Articles

Lubricating Performance of Lanzhou Lily Crude Extract as Natural Additive

Due to environmental concerns and multifunctional requirements, natural additives are a promising alternative to traditional enhancers like metal nanoparticles. Lanzhou lily crude extract (LLCE) was investigated as an additive in PEG400 base oil. Firstly, different contents of LLCE as an additive notably improved physiochemical properties, such as thermal stability, viscosity, and the viscosity index. With 5–10 wt.% of LLCE added in PEG400, the thermal degradation temperature increased by 37.3–49.5 °C. Secondly, the addition of LLCE significantly reduced the friction coefficient and wear rate of the steel disc at 50–150 N compared to pure PEG400 base oil with a reduction degree of up to 30% and 92%. The optimum additive content was 7 wt.%, and further increasing the content of the additive did not bring about obvious improvements, even worsening the product in some cases. Thirdly, the lower friction coefficient and wear rate achieved through the addition of LLCE may be due to the higher viscosity facilitating a thicker lubricating film and the higher polarity providing better chemical affinity with the metallic surface. In summary, LLCE is a promising additive that significantly improves the physicochemical properties and lubricating performance of PEG400 base oil.

Enhanced bone cement for fixation of prosthetic joint utilizing nanoparticles

Bone cement is commonly utilized to secure prosthetic joints in the body because of its robust fixation, stability, biocompatibility, and immediate load-bearing capability. However, issues such as loosening, leakage, and insufficient bioactivity can lead to its failure. Therefore, improving its mechanical, physical, and biological properties is crucial for enhancing its efficiency. This study examines the impact of incorporating four different nanomaterials—Titanium Dioxide (TiO2), Magnesium Oxide (MgO), Calcium Phosphate (Ca3(PO4)2), and Alumina Oxide (Al2O3)—into bone cement on its mechanical, physical, and biological properties. TiO2 and Al2O3 nanoparticles are selected to enhance the compression strength of bone cement, thereby preventing loosening. Magnesium Oxide (MgO) and Ca3(PO4)2 nanoparticles are chosen to improve cell adhesion and reducing the risk of cement leakage. Five specimens were prepared: the first with 100% pure bone cement powder, the second with 98% pure bone cement powder and modified with 2% MgO and TiO2, and the remaining three with 95% pure bone cement powder and modified with 5% varying ratios of MgO, TiO2, Ca3(PO4)2, and Al2O3. Compression, tensile, hardness, and bending strengths were assessed to determine improvements in mechanical properties. Setting temperature, porosity, and degradation were measured to evaluate physical properties. Cell adhesion and toxicity tests were conducted to examine the surface structure and biological properties. The results demonstrated that the modified specimens increased compression strength by 8.14%, tensile strength by 3.4%, and bending strength by 4.96%. Porosity, degradation, and setting temperature in modified specimens increased by 3.24%, 0.64%, and 5.17% respectively pure bone cement values. Cell adhesion in modified bone cement specimens showed normal attachment when scanned with FE-SEM. All of the tested modified specimens showed no toxicity, except for specimens with 2% Al2O3 that showed 25% toxicity which could be averted by employing antibiotics.Graphical

Preparation of crosslinked lignin-polyacrylamide hydrogel with high resistance to temperature and salinity.

In this study, we innovatively prepared a multifunctional lignin crosslinked polyacrylamide (L-cPAM) hydrogel by a sequential two-step strategy of crosslinking of lignin and crosslinked polyacrylamide (cPAM) followed by the polymerization of cPAM. The hydrogen bonding and crosslinking between the molecular chains of lignin and PAM established a rigid and porous network structure, which provided the L-cPAM hydrogel with excellent mechanical strength, thermal stability, and salinity resistance. A series of lignin dosages (0 to 30 %) were investigated during the crosslinking of lignin and PAM. The results showed that the mechanical strength of the obtained L-cPAM hydrogel could be increased by 53.6 % to 180.71 kPa at a lignin dosage of 15 %. Moreover, the recovery coefficient of the L-cPAM hydrogel after 20 compressions could be maintained at 85.28 %, indicating a strong shape recovery ability. After crosslinking cPAM with a lignin dosage of 15 %, the initial thermal degradation temperature was substantially increased from 150 °C to 181 °C and the shape of the L-cPAM hydrogel could also be maintained for over 60 days in 21× 104 mg L-1 brine at 150 °C. The results suggested that this work provides a new method to construct high-temperature and high-salinity resistant hydrogels using lignin and polyacrylamide.

Robust shape memory chlorobutyl rubber/boron nitride polymer nanocomposites for oil-water separation application

BackgroundBoron nitride (h-BN), an excellent 2D material finds exceptional applications in various fields owing to its unique characteristics including excellent hydrophobicity. Incorporation of boron nitride in polymer matrices is a captivating strategy by the scientific community to tune the properties of polymer. Interestingly, the possibilities of incorporating h-BN in chlorobutyl rubber (CIIR) matrix has never been considered and tried till now. Moreover, the use of CIIR to create a clean environment and reduce water pollution is an unexplored area even though the CIIR rubber possess excellent barrier properties. MethodsIn this work, two techniques were used for the fabrication of BNNS/CIIR nanocomposite. We exfoliated h-BN via chemical exfoliation method and tried the reinforcement of CIIR with BNNS via solution intercalation method. Shape memory analysis was performed with the help of stearic acid and oil-water separation analysis was achieved through an easy experimental technique. Significant findingsEnhanced mechanical strength of 11.57 MPa, improved thermal degradation temperature and char yield, higher glass transition temperature of -45.98° were observed for BNNS/CIIR nanocomposite reinforced with higher BNNS loading owing to the uniform distribution and better intercalation of BNNS in CIIR. Excellent shape memory was exhibited by CIIR matrix when reinforced up to 5 g BNNS. In addition, the nanocomposites displayed excellent ability to perform oil-water separation with increase in BNNS loading owing to the good hydrophobic character of h-BN and inherent barrier properties of CIIR. Thus, the study proved successful towards the fabrication of advanced CIIR nanocomposites with excellent shape memory and oil water separation efficiency.

Green Synthesis of Urethane-Linked Tamarind Seed Xyloglucan: Thermal Stability, Antibacterial Properties, andDFT Study.

This study presents a feasible, one-pot synthesis approach for the preparation of a composite biopolymer material derived from tamarind seed xyloglucan (XG) by utilizing isocyanate chemistry. Through a facile reaction process, urethane bonds are formed in XG, resulting in the formation of a crosslinked network. FTIR spectra confirm the successful urethane link formation in XG via the OH-NCO reaction, and CHN analysis provides insights into the elemental composition. The synthesized XG-urethane composite (U-XG) exhibits enhanced thermal stability compared to native XG, with an enhanced degradation temperature (T5%) of 276°C (XG marked T5% at a lower temperature of 163°C). The optimized geometric structure, hydrogen bond types, and hydrogen bond strength of the synthesized U-XG are computationally studied by density functional theory (DFT) at the B3LYP/6-31G(d,p) level. This study also investigates the antibacterial efficacy of both XG and U-XG against a panel of pathogenic bacteria, including gram-positive bacteria such as S. aureus and S. epidermidis, as well as gram-negative E. coli. The U-XG demonstrates superior antibacterial activity against S. epidermidis compared to pristine XG. This research showcases the feasibility of a one-pot synthesis approach for preparing urethane-linked XG with enhanced thermal properties and superior antibacterial activity, offering promising prospects for biomedical and antimicrobial applications.

Comparative study of the synthesis of polyhydroxyalkanoates by cyanobacteria Spirulina platensis and green microalga Chlorella vulgaris

The article presents the results of the study of the growth and synthesis of degradable polyhydroxyalkanoates (PHA) of cyanobacteria Spirulina platensis (Nordst) Geitl. and green microalga Chlorella vulgaris (Beijer), in the cultures of which the production of “green” plastics was studied, including in relation to the dynamics of the fatty acid composition of lipids associated with the formation of PHA. The reorganization of constructive metabolism during the development of both cultures and the dynamics of accumulation of lipids and PHA in cells against the background of a decrease in protein were studied. On a modified BG-11 medium, with a decrease in the NaNO3 concentration to 0.5 g/L and the addition of sodium acetate (3/0 g/L), the yields of polymers for C. vulgaris and S. platensis reached 20.0 and 16.2 %, respectively. The composition and properties of the polymer, which is a homopolymer of 3-hydroxybutyric acid (P(3HB)), were studied using GC, FTIR spectroscopy, HPLC, and DTA. The average molecular weight of P(3HB) samples was determined to be 416–467 kDa; crystallinity was 54–56 % with a gap between the melting point and thermal degradation temperature of 109–114 °C.

Nanocellulose extraction from date palm waste using 1-butyl-3-methylimidazolium hydrogen sulphate.

This study provides insights into nanocellulose production using 1-butyl-3-methylimidazolium hydrogen sulphate ([Bmim]HSO4) as a green solvent, utilizing cellulose derived from date palm waste. Critical hydrolysis parameters were optimized through analysis of variance and response surface methodology. The predicted nanocellulose yield (Y) followed a quadric equation represented by Y=55.48-0.57pH-0.478ST+0.997T-0.006721T2+0.0681pH×ST-0.0681pH×T+0.003833ST×T. The developed empirical model showed excellent predictive accuracy (R2>0.95). The optimized hydrolysis parameters were pH1, a temperature of 80°C, and a stirring time of 45min, resulting in an 80.5% yield of nanocellulose. Scanning electron microscopy showed the nanocellulose's needle like morphology, while transmission electron microscopy indicated an average particle size ranging from 50 to 60nm. Fourier transform infrared spectroscopy confirmed the purity of the nanocellulose by indicating the removal of non-cellulosic components. X-ray diffraction analysis showed a crystallinity index (Crl) of 72.22%, representing a 67.5% increase compared to the Crl raw date waste. Dynamic light scattering showed a hydrodynamic diameter of approximately 100nm. Thermal stability performed using thermogravimetric analysis indicated a high initial degradation temperature (Tonset) of 233°C, while differential scanning calorimetry confirmed the absence of melting transitions up to 250°C, underscoring the material's exceptional thermal stability. This study highlights the robust capability of [Bmim]HSO4 to produce high quality nanocellulose from lignocellulose-derived cellulose, broadening its application beyond the previously reported use with microcrystalline cellulose to produce nanocellulose.

THE EFFECTS OF SEPIOLITE LOADINGS ON MECHANICAL, THERMAL, AND MORPHOLOGICAL CHARACTERISTICS OF NATURAL RUBBER/EPOXIDISED NATURAL RUBBER (NR/ENR-25) BLENDS

Sepiolite has been used widely as nanofillers to improve the properties and compatibility of rubber blends, and due to its magnesium silicate hydrates contents, the sepiolite may also function as a thermal stabilizer. These works investigate the effects of sepiolite loadings on curing, mechanical, thermal, and morphological characteristics of natural rubber/epoxidized natural rubber (NR/ENR-25) blends. The blends were made using a two-roll mill technique using standard vulcanization reagents of sulfur and carbon black as the main filler, and their vulcanization characteristics were investigated using the rheometry technique. Furthermore, the thermal, mechanical, and morphological characteristics of the blends were evaluated using thermogravimetry, tensile tests, and electron microscopy, respectively. It was found that an increase in the sepiolite loadings decreased scorch times (ts2 and t90), whereas optimum sepiolite loading with higher tensile strength was 3 phr, which lowered down when the sepiolite loading was increased up to 9 phr. The thermogram of blend specimen with 3 phr sepiolite loading also exhibited superior thermal stability, that is, has higher degradation temperature at 5% weight loss. Fracture surface SEM photographs of the blend specimens showed finely distributed sepiolite particles at optimum sepiolite loading 3 phr and exhibited agglomerations when the loadings were increased up to 9 phr.

Tailoring graphitized cellulose nanocrystal morphologies for robust barrier and mechanical enhancement of PPC composites for green active packaging

Both nanocellulose and graphene nanosheets serve as exceptional fillers for biopolymers. However, there are limited materials that effectively combine the properties of these two fillers in PPC to enhance their overall properties. This study presents a meticulous approach to producing graphitized nanocellulose (GCNC) with tailored rod-like (R-GCNC) and spheres-like (S-GCNC) under low-temperature and ambient-pressure conditions. The formation and integration of the reinforcement network within the PPC matrix were compared by modulating these morphologies. The R-GC3%, with its stronger hydrogen bonding interactions, achieved a more optimal combination of properties than S-GC3%. Significantly, R-GCNC and PPC formed a robust reinforcement network, resulting in remarkable reductions of approximately 153 % in water absorption and 1669 % in water vapor permeability. Significantly, the mechanical properties of PPC were improved by 95 % in tensile strength and 1038 % in Young's modulus due to improved dispersion of R-GCNC with higher aspect ratio. In addition, R-GC3% had the highest glass transition temperature of 35.1 °C, and a maximum degradation temperature increased by 16.5 °C. The PPC/GCNC composites exhibited outstanding UV shielding, antioxidant properties, and rapid degradation rates. This study introduces a practical method for choosing suitable GCNCs as reinforcing agents to produce innovative green materials for the active packaging sector.

Characterization of treated empty fruit bunches by thermogravimetric analysis (TGA)

This research investigates the thermal degradation characteristics of treated empty fruit bunches (EFB) using thermogravimetric analysis (TGA), contributing to circular economy promotion by encouraging the use of agricultural by-products in the energy sector. EFB feedstock was prepared by immersing 100g of residue in 1.8 liters of distilled water for 40 minutes at room temperature (~30°C). Results show that this treatment reduced ash content by approximately 2.74 wt%. TGA data reveals that untreated EFB exhibited greater weight loss compared to treated EFB, with the latter showing shifted decomposition processes at higher thermal degradation temperatures. The study explores ash’s catalytic influence, providing insights into weight loss patterns and decomposition temperature ranges. This enhanced understanding of biomass behavior provides valuable data for optimizing biomass-based energy systems, further advancing sustainable energy solutions and resource efficiency.

Characterization of bio-lubricants with nanoparticles additives

ABSTRACT It is well known that lubricating oils reduce the friction coefficient between two surfaces in contact. Since petroleum lubricants are toxic and have a low biodegradability, they are typically not appropriate for the environment. As a result, as public worries about a pollution-free environment grow, so does the demand for lubricants that are acceptable to the environment. The primary rationale for utilizing vegetable oils in forthcoming bio-lubricant formulations is their high lubricating performance, low toxicity, sustainable, and biodegradability. Plant oils hold great potential as a foundational fluid for bio-lubricants, since their synthetic and vegetable oil-based esters provide the most environmentally friendly option for creating lubricants. In this study, Jatropha and Jojoba raw oil were chemically modified via epoxidation followed by transesterification to produce bio-lubricants. Thus, the aim of this work is to develop a bio-lubricant from jatropha and jojoba methyl ester, further adding nanoparticles multiwalled nanotubes and titanium dioxide for improvement of tribological properties. The chemical modification of the jatropha and jojoba oil results in a decrease in iodine value, resulting in the breaking of carbon bonds. Viscosity tests were performed using the Anton Par MCR 92 Rheometer, with temperature ranging from 30°C to 80°C. Thermal stability measurements of bio-lubricants were performed using PerkinElmer’s Thermogravimetric analyzer − 4000 instrument and thermal degradation temperature for Epoxidized Jatropha – sulfuric acid, Epoxidized Jatropha – hydrochloric acid, Epoxidized Jojoba – sulfuric acid and Epoxidized Jojoba – Hydrochloric acid samples are 238°C, 224°C, 230°C, and 244°C, respectively. The 94.68% and 79.85% reduction in wear was obtained for Epoxidized Jojoba with hydrochloric acid, titanium dioxide and epoxidized Jatropha with sulfuric acid, multiwalled carbon nanotubes in comparison with their epoxidized samples. The coefficient of friction of Epoxidized Jatropha with sulfuric acid, multiwalled carbon nanotubes and Epoxidized Jojoba with Hydrochloric acid, Titanium dioxide sample was found to be 0.061 and 0.059, respectively.

Mechanical, thermal and morphological analysis of polylactic acid‐woven glass fiber composites fabricated by additive manufacturing

AbstractPolylactic acid (PLA), a biodegradable thermoplastic, is being used significantly in a wide range of applications because of its environmentally friendly nature. 3D printing is an innovative technique that is used to fabricate polymer composites with complex contours and high precision. Conventional 3D printing technologies use fiber reinforcement in the form of filament. However, fibers in the form of sheets, when used in composite materials, improve the distribution of load and enhance the multi‐directional strength. This study investigates the improvement in the tensile strength of PLA‐based composite by integrating woven glass fibers (WGF) during 3D printing processing. The composites were fabricated using an FDM‐based 3D printer where the WGF sheet was used as reinforcement and PLA filament was used as the matrix material. The main input parameters consist of the number of WGF layers and the orientation of the WGF. Taguchi orthogonal array was used to fabricate composite samples with different combinations of input parameters and then these samples were tested to evaluate the tensile properties. The finding shows that PLA composites reinforced with four layers of glass fiber at 0/90° fiber orientation showed the highest tensile strength of 52.85 MPa and a thermal degradation temperature of 330.49 °C.Highlights 3D printing of WGF‐PLA composite and mechanical characterization. The composite specimen showed the highest tensile strength of 52.85 MPa. The thermal degradation temperature reached 330.49 °C in TGA analysis. ANN predicted the optimal combination of 4 fiber layers with 0/90° orientation. Uniform PLA deposition reduced voids and enhanced interlayer adhesion.

Advances in nanomaterials for radiation protection in the aerospace industry: a systematic review.

Nanomaterials stand out for their exceptional properties and innovative potential, especially in applications that protect against space radiation. They offer an innovative approach to this challenge, demonstrating notable properties of radiation absorption and scattering, as well as flexibility and lightness for the development of protective clothing and equipment. This review details the use of polymeric materials, such as polyimides (PIs), which are efficient at attenuating ultraviolet (UV) radiation and atomic oxygen (AO). For example, polyimides show a decrease in elongation at break by 10% after exposure to VUV radiation of 2000 equivalent solar hours (ESH). The thermal stability under vacuum ultraviolet (VUV) irradiation shows that colorless polyimides like CPI-T/Al exhibit an onset degradation temperature of 451°C, while CPI-L/Al shows a degradation onset of 439° C. Additionally, advancements in composite materials for gamma and neutron radiation shielding are covered. Materials such as fluorinated hyperbranched polyimides (FHBPI) display a decomposition temperature of approximately 450°C, which ensures structural integrity during space missions involving radiation. Radiation absorption and scattering properties of these composites are assessed, with materials such as W-Bi2O3 demonstrating a high linear attenuation coefficient (LAC) of 2.5 MeV, enhancing their efficiency in protecting against gamma radiation. Mechanical and optical changes, such as a 15% increase in solar absorbance after exposure to VUV, are critical for prolonged space missions. Moreover, the integration of nanoparticles like graphene and carbon nanotubes into polymers has proven to be an efficient strategy for improving the shielding properties and stability of materials. Nanocomposites like BNTT-Ti display a neutron transmission reduction of 20%, further validating their potential for space applications. Future investigations will focus on optimizing the functionality, manufacturing, and compatibility of composite materials, as well as validating their performance under actual space mission conditions. Collaboration among material scientists, aerospace engineers, and space agencies is vital to transforming laboratory discoveries into viable solutions for radiation protection in space.

Development of Immediate Release Tablet Formulations of Lornoxicam with Hot Melt Extrusion Based Three-Dimensional Printing Technology

Introduction This study aims to develop immediate release tablet formulations of lornoxicam (LRX) using hot melt extrusion (HME)-based fused deposition modelling (FDM) focusing on the adjustment of drug release by arranging infill densities and evaluating microcrystalline cellulose II (MCC II) as a disintegrating agent for HME-FDM purposes. LRX is a poorly soluble drug that exhibits pH-dependent solubility with a high thermal degradation temperature. These characteristics make it an ideal model drug for the HME-based FDM technique. Methods Various filament formulations were extruded using an extruder, and suitable filaments were used to produce 3D-printed tablets. Filaments and tablets were characterized. Dissolution studies were performed on tablets with different infill densities. DSC, FTIR, XRD, and SEM analyses were conducted. Results Although the solubility of LRX increases with pH, disintegrating agents such as MCC II had a more significant effect on the dissolution of LRX than sodium bicarbonate, which was used as the alkalinizing pore-forming agent. Dissolution studies revealed that the dissolution of LRX was enhanced by tablet erosion. Tablet erosion increased as the infill density decreased, and an immediate release profile was reached with tablets having 25% infill density. Despite the availability of conventional immediate release LRX tablets, this newly developed formulation offers the potential to be modulated for personalized theraphy via the 3D printing technique. Conclusion This study demonstrates the feasibility of HME-based FDM printing technology for producing immediate-release LRX tablets with consistent quality, highlighting the utilization of MCC II as a disintegrating agent that enhances LRX dissolution in this process.

Harnessing Imine Chemistry for the Debonding-on-Demand of Polyurethane Adhesives.

Traditional adhesives often result in irreversible bonds, hindering disassembly and recycling processes. In response to the growing demand for sustainable practices, researchers have explored alternative bonding solutions. Debonding-on-demand adhesives represent a breakthrough, enabling selective weakening or breaking of adhesive bonds when desired and facilitating efficient disassembly, repair, and recycling of bonded materials. This has profound implications across industries, including packaging, footwear, automotive, and electronics, where the recycling of bonded components plays a crucial role in resource conservation. Herein, we present the incorporation of an imine-based polyol derived from vanillin and polyetheramine into a model, one-component, polyether-based polyurethane adhesives. Such systems retained their thermal performance, exhibiting onset degradation temperatures of ∼320 °C and glass transition temperatures of ∼-50 °C, similar to the reference adhesive. Additionally, they demonstrated adhesive performance comparable to that of the reference system, with lap-shear strengths ranging from 1.7 to 2.1 MPa. In addition to that, imine polyol incorporated adhesives offered enhanced recyclability through on-demand debonding of the bonded substrates to obtain adhesive-free surfaces by acidic hydrolysis of the imine functional groups. These findings undoubtedly contribute to the advancement of sustainable material practices and promote a circular economy, emphasizing the importance of adhesive technology in addressing environmental challenges.

Functional Nanofibers for Active Packaging: Elenolic Acid‐Loaded Chitosan/PEO Blends

ABSTRACTThe aim of this study is to create electrospun nanofibers based on chitosan/PEO (polyethylene oxide) and elenolic acid and to characterize them as active film materials. Elenolic acid was incorporated into the chitosan/PEO polymer matrix at varying concentrations (0%, 1%, 2%, and 5%), and its effects on solution properties such as conductivity and viscosity were investigated. The morphological structure of the nanofibers was assessed using scanning electron microscopy (SEM), showing an unimodal size distribution for all samples except the one with the highest elenolic acid concentration (E_5). Additionally, water vapor permeability (WVP) and thermal properties of the films were evaluated. The WVP of the fibrous films ranged between 7.086 ± 0.569 and 2.340 ± 0.259 × 10−10 g−1 s−1 Pa−1, with elenolic acid incorporation reducing the films' permeability. The onset degradation temperature of the samples decreased by 100°C with the addition of elenolic acid. FTIR results confirmed successful encapsulation of elenolic acid. The films' antioxidant activity and total phenolic content were also measured and 5% elenolic acid‐loaded nanofibers showed strong antioxidant activity (almost 92%) with total phenolic content as 25.92 ± 1.17 (mg GAE/g film). Furthermore, the antimicrobial activity of the fibrous films was tested against common foodborne pathogens, including E. coli (G−) and S. aureus (G+). Films containing 2% and 5% elenolic acid exhibited inhibitory effects (inhibition zone between 13.5 and 18.5 mm) between both microorganisms.

Effect of Composition on Physical, Mechanical, and Thermal Properties of Oil Palm Empty Fruit Bunch Epoxy Resin Biocomposite

Oil palm empty fruit bunches (OPEFB) are wastes from oil palm processing. The objective of this work is to study the effect of composition on the physical, mechanical, and thermal properties of OPEFB epoxy resin biocomposite. Particles of OPEFB (100 mesh) were mixed with epoxy resin with the ratio of OPEFB to epoxy resin 60/40, 70/30, 80/20, and 90/10 (vol.%/vol.%). Biocomposites were produced by a press method at room temperature with 9 tons-load. The physical properties (density, porosity, water absorption, thickness swelling) of the biocomposite were evaluated. The mechanical properties (modulus of rupture and modulus of elasticity) of biocomposite were determined by using a universal testing machine. The thermal gravimetric analyzer (TGA) was used to examine the thermal properties of the biocomposite. The results show that the density of biocomposite is 1.18 g/cm3 for 60 vol.% of OPEFB composition. It decreases significantly as the OPEFB composition increases. For 60 vol.% of OPEFB, the porosity, water absorption, and thickness swelling of biocomposite (after soaking in water for 24 hours) are 11.9%, 10.1%, and 6.5%, respectively. All these values increase significantly with the increase of OPEFB composition. For 60 vol.% of OPEFB, the modulus of rupture (MOR) and modulus of elasticity (MOE) of biocomposite are 2.31 kgf/mm2 and 267 kgf/mm2, respectively. The values of MOR and MOE decrease significantly with the increase in OPEFB composition. TGA results show that degradation of biocomposites occurs significantly at 350°C for 60 vol.% OPEFB. The degradation temperature reduces as the composition of OPEFB increases. In general, the physical, mechanical, and thermal properties of biocomposites decrease with increasing OPEFB composition. This happens because the bond between the matrix and the particles decreases as the OPEFB composition increases. The maximum OPEFB composition that can be used for particleboard applications is 80 vol.%, which meet the ANSI 208.1-2009 requirements for application as grade M-2 particleboard.

Frontal Polymerization of Phytic Acid Containing Hexaacrylate, Triacrylate, and Fillers

ABSTRACTFrontal polymerization (FP) has been used in the application of coatings, adhesive, and composites. In this work, a new bio‐based phytic acid monomer, known as phyto‐urethane acrylate (PUA) with demonstrated flame retardant abilities, has been incorporated and frontally polymerized into a base formulation composed of trimethylolpropane triacrylate (TMPTA), a peroxide thermal radical initiator and fumed silica. This is the first report of a hexaacrylate monomer cured via FP. Four different fillers (magnesium hydroxide, nano zinc oxide, milled carbon fiber, and melamine), known for their flame‐retardant properties were also incorporated into the base formulation along with PUA resin. The front velocity, front temperature and viscosity were studied for all formulations in detail. Thermal analysis of the composites showed that composites prepared in this research have high glass transition temperature above 200°C and degradation temperature above 300°C. Surface properties before and after burning events were captured via SEM, and it was found that formulation containing PUA resin showed bubble morphology, which indicates char formation. Microcomputed tomography (μ‐CT) showed that quantity and morphology of the pores in the composites can be altered with the incorporation of PUA resin and fillers.

Physical, Morphological, Tensile, and Thermal Stability Characteristics of Novel Tinospora Cordifolia Natural Fiber

ABSTRACT This article presents an analysis on the characterization of the natural fibers from the stem of Tinospora cordifolia plant/vine. Several characterizations/measurements were carried out on the water retted fibers to ascertain their properties. These included diameter and density measurements, X-ray Diffraction (XRD) analysis, chemical composition by gravimetric method, Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, single fiber tensile tests, and Thermogravimetric analysis (TGA). The fibers had an average diameter of 202 µm and density of 0.6 g/cm3. The SEM images revealed a rough surface which highlights the potential for good adhesion with the polymer matrix. The Crystalline Index (C.I) and Crystallite Size (C.S) obtained from the XRD spectra were 60.19% and 2.56 nm, respectively. Amount of cellulose, hemicellulose, lignin, and extractives in the fiber were 65%, 12%, 17%, and 6%, respectively. FTIR analysis revealed the presence of major constituents of the natural fiber such as cellulose, hemicellulose, and lignin. The tensile strength, Young’s modulus, and percentage elongation at break of the fiber were 484 ± 100 MPa, 22 ± 4 GPa, and 3.8 ± 1%. The onset of thermal degradation (Tonset) and maximum thermal degradation (Tmax) temperatures were 259°C and 368°C, respectively. Mechanical and thermal properties of the fiber were satisfactory when compared with popular natural fibers.

Isolation and characterization of cellulose from spent ground coffee (Coffea Arabica L.): A comparative study

This study compares several methods, such as sodium chlorite, nitric acid, and hydrogen peroxide treatments with alkali pre-treatments, for efficiency of extracting cellulose from spent ground coffee. The extracted cellulose was characterized by Fourier transform infrared spectroscopy (FTIR), x-ray diffractometry (XRD), thermogravimetric analysis (TGA), colour analysis, chemical composition, and particle size analysis. FTIR confirmed the removal of non-cellulosic components from coffee, which correlates with chemical composition and colour analysis results. The highest cellulose content (96.7 %) and the highest whiteness index (71.24) were obtained for the cellulose materials extracted using nitric acid-sodium chlorite and sodium chlorite with alkali pre-treatments, respectively. XRD data reveals that the treated coffee presented exhibited a higher crystallinity index compared to the untreated one. The highest increase in crystallinity index (from 54.9 % to 66.3 %) was achieved for the cellulose extracted using a 20 % hydrogen peroxide treatment with alkali pre-treatment. The maximum degradation temperature of the spent ground coffee increased from 292.0 to 310.5 °C after treatment with 10 wt% hydrogen peroxide and alkali pre-treatment. In summary, these findings highlight the great potential of spent ground coffee as a source of cellulose.