Anhydride Content Research Articles

3D bioprinting of fish skin-based gelatin methacryloyl (GelMA) bio-ink for use as a potential skin substitute.

Gelatin methacryloyl (GelMA), typically derived from mammalian sources, has recently emerged as an ideal bio-ink for three-dimensional (3D) bioprinting. Herein, we developed a fish skin-based GelMA bio-ink for the fabrication of a 3D GelMA skin substitute with a 3D bioprinter. Several concentrations of methacrylic acid anhydride were used to fabricate GelMA, in which their physical-mechanical properties were assessed. This fish skin-based GelMA bio-ink was loaded with human adipose tissue-derived mesenchymal stromal cells (ASCs) and human platelet lysate (HPL) and then printed to obtain 3D ASCs + HPL-loaded GelMA scaffolds. Cell viability test and a preliminary investigation of its effectiveness in promoting wound closure were evaluated in a critical-sized full thickness skin defect in a rat model. The cell viability results showed that the number of ASCs increased significantly within the 3D GelMA hydrogel scaffold, indicating its biocompatibility property. In vivo results demonstrated that ASCs + HPL-loaded GelMA scaffolds could delay wound contraction, markedly enhanced collagen deposition, and promoted the formation of new blood vessels, especially at the wound edge, compared to the untreated group. Therefore, this newly fish skin-based GelMA bio-ink developed in this study has the potential to be utilized for the printing of 3D GelMA skin substitutes.

Novel vapor phase furfurylation for enhancing the dimensional stability of bamboo

Bamboo holds great promise as a versatile material in construction and engineering. However, its inherent hydrophilic nature, particularly within its cell walls, presents challenges for dimensional stability, limiting its widespread use. Addressing this challenge, vapor phase furfurylation (VPF) has emerged as a promising technique for bamboo modification. In this study, we applied VPF to bamboo for the first time, resulting in a significant transition towards hydrophobicity and a remarkable enhancement in dimensional stability (ASE > 50 %). Employing a multifaceted approach, we investigated the distribution gradient and penetration depth of FA resin within furfurylated bamboo using advanced methodologies such as scanning electron microscopy (SEM), nanoindentation, dynamic vapor sorption (DVS), and imaging FT-IR microscopy, demonstrating the improvement in dimensional stability is attributed to cell wall bulking from FA resin infiltration. Through meticulous parameter refinement, we identified an optimized protocol comprising 40 h of VPF exposure, a VPF temperature of 115 °C, and a 4.5 % concentration of maleic anhydride (MA). This tailored VPF methodology holds promise for enhancing the dimensional stability of bamboo while minimizing FA consumption, thus expanding its potential applications in construction and furniture industries.

Tunning the hydrophobic performance and thermal stability of pectin film by acetic anhydride esterification

Pectin, a polysaccharide found in plant cell walls, is characterized by a high abundance of hydroxyl groups and carboxylic acid groups, which results in a strong affinity for water and limits its suitability as a film material. This study aimed to modulate the esterification degree of PEC films by adjusting the concentration of acetic anhydride, and assess the impact of acetic anhydride esterification modification on the properties of the resultant PEC films. The results demonstrated successful grafting of acetic anhydride onto the galacturonic acid ring in the PEC molecule through the esterification process. The hydrophobicity, thermal stability, barrier properties, and mechanical properties of the esterified PEC films were investigated. Among the various concentrations tested, the E-PEC-0.25 film exhibited the highest contact angle of 103.46° and tensile strength of 33.44 MPa, showcasing optimal performance. The E-PEC-0.1 film achieved the highest esterification degree of 0.94 and elongation at a break of 21.11 %. It also exhibited the transparency of 11.66 and the lowest water vapor transmission rate of 0.56 g·mm/(m2·h·kpa). Additionally, TGA and DSC tests revealed enhanced thermal stability of the esterification-prepared films. These findings highlight the potential of acetic anhydride tuning as a promising strategy for optimizing pectin film production.

Optimization of malic anhydrate concentration in manufacturing PP-g-MA compatibilizer on test percent of grafting degree

The difference in polarity means that two or more materials cannot react, a connecting material such as a compatibilizer is needed to react between polar and non-polar materials. This research aims to determine the effect of maleic anhydride (MA) concentration on the process of grafting MA onto polypropylene (PP) chains with the help of benzoyl peroxide (BPO) as an initiator. The method used to mix these two materials uses the blending method using an internal mixer instrument and testing the percent degree of grafting using the titration method with three repetitions of the test.The research results showed that the highest percent grafting degree occurred at a concentration of 86% PP, 11% MA, and 3% BPO, with a value of 10.28%. The Spectroscopy Fourier Transform Infrared (FTIR) analysis of Polypropylene grafted maleic anhydride (PP-g-MA) showed the presence of new peaks at wavenumbers 1707cm-1 and 1162 cm-1.Increasing the concentration of maleic anhydride had no effect on increasing the percent degree of grafting.

Fused Filament Fabrication of WC-10Co Hardmetals: A Study on Binder Formulations and Printing Variables

This research explores the utilization of powder fused filament fabrication (PFFF) for producing tungsten carbide-cobalt (WC-10Co) hardmetals, focusing on binder formulations and their impact on extrusion force as well as the influence of printing variables on the green and sintered density of samples. By examining the interplay between various binder compositions and backbone contents, this study aims to enhance the mechanical properties of the sintered parts while reducing defects inherent in the printing process. Evidence suggests that formulated feedstocks affect the hardness of the sintered hardmetal—not due to microstructural changes but macrostructural responses such as macro defects introduced during printing, debinding, and sintering of samples. The results demonstrate the critical role of polypropylene grafted with maleic anhydride (PP-MA) content in improving part density and sintered hardness, indicating the need for tailored thermal debinding protocols tailored to each feedstock. This study provides insights into feedstock formulation for hardmetal PFFF, proposing a path toward refining manufacturing processes to achieve better quality and performance of 3D printed hardmetal components.

Mechanical Properties of Aramid Fiber Fabrics and Composites Enhanced by Phthalic Anhydride Catalyzed with Anhydrous Aluminum Chloride

The surface modification of aramid fiber plain fabric (PPTA) was conducted through phthalic anhydride treatment and anhydrous aluminum chloride (AlCl3) catalysis, aiming to enhance the interfacial bonding strength between aramid fiber fabric and bisphenol A diglycidyl ether (DGEBA) resin. The surface morphologies and structures of PPTA fiber before and after modification were characterized using scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and X-ray diffractometry. The mechanical properties of the PPTA/DGEBA composite were evaluated using a universal mechanical testing machine. The results demonstrate that when the concentration of phthalic anhydride is 0.3 mol/L, the tensile strength, bending strength and interlaminar shear strength of PPTA/DGEBA composites reach the maximum value, which are increased by 17.94%, 44.18%, and 15.94% compared with the unmodified sample, respectively. After a 0.5-h catalytic modification, the PPTA/DGEBA composites exhibited significantly enhanced tensile strength, bending strength, and interlaminar shear strength, achieving respective increments of 32.28%, 24.91%, and 29.10% compared to the modified samples without catalyst addition. Moreover, the overall mechanical properties of the aramid fiber fabrics and composites were substantially improved, which are more suitable for structural applications.

Evaluation of the effect of the incorporation of poly(lactic acid) and maleic anhydride in the thermoshrinkage of films from thermoplastic starch

AbstractStudies on the property of shape memory in thermoplastic starch (TPS) have shown good results, making such starch a suitable candidate for use in shrink packaging. It is however necessary to evaluate blending it with other bioplastics that would improve its properties while maintaining heat shrinkage. This article thus shows the evaluation of the incorporation of different concentrations of polylactic acid (PLA) and maleic anhydride (MA) as coupling agent and their effect on shrinkage and the changes in structure of the films obtained by blown film extrusion. In most of the blends, the incorporation of PLA and MA was found to favor film shrinkage, obtaining values of up to 55% due to the fact that the interaction between TPS and PLA increased with the incorporation of MA. This was corroborated by the % of MA grafted, thermogravimetric analysis (TGA), rheological and structural tests. This allowed generating a greater molecular orientation of the films, thereby obtaining greater shrinkage. It was determined that the incorporation of PLA and % MA grafted generated good shrinkage results due to the physical and chemical crosslinking achieved in the processing of the blends in the presence of MA, enhancing their application as packaging.

Profile of the Effectiveness Factor under Optimal Operating Conditions for the Conversion of Ortho-Xylene to Phthalic Anhydride in a Fixed-Bed Tubular Reactor

The objective of this research is to find the effectiveness factor of the catalyst particles for the most favorable conditions of the phthalic anhydride production in a fixed bed reactor, with the aim of achieving the highest rate of phthalic anhydride production compared to other secondary products and analyzing the areas of lower effectiveness for the modification of the reactor design. Initially, the material and the energy balances in the catalytic bed are solved to obtain the concentration and temperature profiles based on the radius and length of the reactor, using polymath software(Polymath® v6.2 Software Minitab 19 Matlab 2019) with the data from literature. Once the profiles reproducibility was verified using the initial data (inlet temperature, pressure in the reactor, reactor wall temperature, reactor radius and mass flow rate) the experimental design 35 carry out, which generates 243 “experiments”, whose response variable (phthalic anhydride concentration) was obtained using Matlab. Subsequently, the variables were analyzed using the Minitab 18® that, through the response surface analysis method, allowed us to obtain the optimal values of the tested variables. Then, Subsequently, material and energy balances coupled with Fourier and Fick’s laws, along with the effectiveness factor equation, were applied, resulting in the generation of 9 coupled differential equations. Upon implementing the finite difference method, this yielded 90 nonlinear algebraic equations, which were solved using the Polymath software. A total of 78 particles were preselected based on their radial and axial positions to determine the effectiveness factor profile, with values ranging from 0.83 to near unity. The lower values correspond to the points with higher temperature, as evidenced by the calculations performed.

Improving the functional properties of rice glutelin: impact of succinic anhydride modification

SummaryRice glutelin is poorly soluble which restricts its potential food application. Succinylation is a chemical modification that improves the solubility of proteins by derivatising the ɛ‐amino group of lysine residues. In this study, rice glutelin was modified by succinic anhydride at different succinic anhydride concentrations (10%, 20%, 30%, 40%, and 50%). The succinylated rice glutelin samples showed enhanced solubility, reduced particle size, and increased absolute zeta potential values. The emulsifying and foaming properties of succinylated rice glutelin were also significantly improved. Moreover, SEM revealed that the surface of succinylated rice glutelin had small pits and protrusions. These results suggest that succinylation can effectively improve the functional properties of rice glutelin, which will facilitate its application in the food industry.

Photoluminescence Studies of DoF Effect on the Photopolymerization Reaction of a GelMA‐Based Monomers for Tissue Engineering

AbstractIn the present work methacrylated gelatin (GelMA) is obtained at different methacrylate anhydride concentrations (5.8% V/V and 10% V/V), different reaction times (1 h and 3 h), and under pH control. A ninhydrin test and NMR are used to determine the degree of functionalization (DoF) of the samples showing that pH controlling produces better functionalization degrees than an increase in methacrylate anhydride concentration or longer reaction times. The photopolymerization process of GelMA samples is studied by time‐resolved photoluminescence at different photoinitiator (PI) concentrations: 0.5%w/V, 1%w/V, and 2%w/V. An increase in PI concentration and DoF produces changes in the crosslink. The 2%w/V concentration produces a higher reaction speed in the first 10 minutes and requires longer times to end the reaction. No significant differences were found in the use of smaller concentrations.This article is protected by copyright. All rights reserved

The effect of photooxidation aging on the cohesion and interfacial adhesion behavior of epoxy asphalt with a composite acidic curing system based on molecular simulation

AbstractThis paper investigated the cross‐linking network structure of epoxy asphalt (EA) with the different ratio of composite curing agents, and further determined the effect of photooxidation aging on the tensile and interfacial adhesion behavior of EA with different cross‐linking network structures through molecular simulation. Based on the molecular models of EA and the interface model between EA and aggregate, the crosslinking network structural characteristics and tensile mechanical behavior were determined. The interfacial adhesion behavior and the mechanization were further studied. The results indicate that 20‐EA and 6‐EA have an epoxy resin cross‐linked network with uniform pore structure and phase distribution. 2‐EA showed a denser cross‐linking network and uneven aggregation phenomenon. Photooxidative aging alleviated the aggregation phenomenon. A dense cross‐linking network improved the tensile strength and the ability of tensile performance to resist photooxidation aging. The interface of EA‐quartz exhibited higher adhesion strength than EA‐calcite due to the closer distance and stronger nonbonding interactions between EA and quartz. The low anhydride content and photooxidation aging made EA approach to the aggregate interface, increasing nonbonding interaction and interfacial adhesion strength. In addition, quartz aggregates were more suitable for application in EA mixtures due to the higher interfacial adhesion strength and lower water sensitivity.

Effect of 4-META on microtensile bond strength of cements to ceramics

Background: This study assessed the effect of different concentrations of 4-methacryloyloxyethy trimellitate anhydride (4-META) added to silane on microtensile bond strength (µTBS) of light-cure and dual-cure resin cement to hybrid and zirconia-reinforced lithium silicate ceramics. Materials and Methods: This in vitro, experimental study was conducted on 32 Celtra Duo and 32 VITA Enamic ceramics bonded to Allcem Veneer light-cure and Allcem dual-cure resin cements using silane impregnated with 4-META in 0%, 2.5%, 5%, and 10 wt% concentrations in 16 groups (n = 4). The µTBS of specimens was measured by a universal testing machine and analyzed by the Kruskal–Wallis and Mann–Whitney tests, and the mode of failure was determined under a stereomicroscope and analyzed by the Chi-square test (alpha = 0.05). Results: The lowest mean µTBS was recorded in the Enamic ceramic group with 4-META (0%) bonded to dual-cure cement (14.26 MPa), and the highest mean µTBS was recorded in Enamic ceramic with 4-META (10%) bonded to light-cure cement (18.59 MPa) (P < 0.001). The µTBS of Celtra Duo was significantly higher than that of Enamic in bonding to light-cure cement using 4-META (2.5%) (P = 0.003). All failures (100%) were adhesive in most groups. The frequency of adhesive failure was the lowest (90%) in Celtra Duo bonded to dual-cure cement with 4-META (5%). Conclusion: According to the results of this pilot study, the addition of 4-META (10%) to silane caused a significant improvement in µTBS to light-cure cement. The addition of 4-META in all concentrations significantly improved the µTBS to Enamic ceramic in the use of dual-cure cement; however, it had no significant effect on µTBS of Celtra Duo. Nonetheless, the results should be interpreted with caution due to the relatively small sample size.

Electrochemical properties of MCDI-utilized PVA/SSA/GA cation exchange membrane

Membrane capacitive deionization (MCDI), an alternative desalination technology that uses a voltage between two electrodes that are covered with ion-exchange membranes to remove salt, has been drawing a lot of research attention. It has been demonstrated that the desalination performance in terms of salt removal and energy efficiency can be maximized when ion-exchange materials are incorporated on the electrodes in MCDI. In this study, the electrochemical properties of the MCDI electrodes coated with PVA/SSA/GA cation exchange membrane were intensively investigated, specifically the effect of sulfosuccinic acid (SSA) and glutaric anhydride (GA) content in the cross-linking reaction with polyvinyl alcohol (PVA). The presence of SSA in the cation exchange membrane helps improve its conductivity, as proven by the electrochemical measurements via cyclic voltammetry and galvanostatic charge-discharge. As a result, the salt adsorption capacity was also enhanced in the addition of SSA and GA into the PVA chain. The PVA/SSA/GA cation exchange membrane is proved to be an inexpensive, environmentally friendly and suitable candidate to be utilized in the MCDI systems. ® 2022 Journal of Science and Technology - NTTU

Fabrication of a new type of polyvinyl alcohol/sulfosuccinic acid/glutaric anhydride cation exchange membrane for desalination using membrane capacitive deionization

Nowadays, the lack of clean water is becoming a serious problem, due to the increasingdemand for clean water, along with global climate change. Desalination of sea water orbrackish water has been considered as a practicable method to supply clean water. Amongdesalination technologies, membrane capacitive deionization has emerged for the last 15years as an alternative method and received a lot of research attention since then. In thisstudy, low-cost and ecofriendly polyvinyl alcohol/sulfosuccinic acid/glutaric anhydridecomposite membranes were fabricated through the crosslinking reaction of sulfosuccinicacid and glutaric anhydride with polyvinyl alcohol. The effect of sulfosuccinic acid andglutaric anhydride content was investigated. The presence of SSA in the cation exchangemembrane, which was proven by FT-IR, helps improve its water uptake (98.5 % comparedto 38.2 %) as well as cation exchange capacity (1.993 mM/g compared to 0.156 mM/g).The polyvinyl alcohol/sulfosuccinic acid/glutaric anhydride composite solution wascoated on the electrode, and the membrane's ability to desalinate water was assessed. Themembrane-coated electrode exhibited enhanced salt adsorption capacity and shorterdesalination time (13.4 minutes compared to 85.3 minutes) in comparison with theuncoated commercial electrode, indicating that the polyvinyl alcohol/sulfosuccinicacid/glutaric anhydride membrane is a suitable candidate to be utilized in the membranecapacitive deionization systems.® 2022 Journal of Science and Technology - NTTU

Optimizing bio-bitumen mixes through response surface methodology

Bio-bitumen, a sustainable alternative to petroleum-based bitumen, is gaining popularity owing to its environmental advantages and potential to address depleting crude oil sources. The purpose of this study is to use Response Surface Methodology (RSM) to optimise bio-bitumen characteristics for sustainable pavements. Bio-bitumen is produced by combining conventional bitumen with biochar, cashew nutshell liquid, waste engine oil, and phthalic anhydride. This study uses RSM to investigate how these components (biochar, cashew nutshell liquid, waste engine oil, and phthalic anhydride) influence important bio-bitumen properties (penetration, ductility, softening point, and elastic recovery). A 2^4 factorial design with 27 trials was employed to optimise the mixing procedure. Statistical analysis, employing visualizations like contour plots and surface plots revealed an optimum bio-bitumen combination having 15% biochar, 1.71% cashew nutshell liquid, 0% waste engine oil, and a phthalic anhydride concentration ranging from 4.54% to 7.5%. This study illustrates the efficacy of RSM in optimising bio-bitumen for sustainable pavements, paving the way for more environmentally friendly road construction.

Optimizing bio-bitumen mixes through response surface methodology

Bio-bitumen, a sustainable alternative to petroleum-based bitumen, is gaining popularity owing to its environmental advantages and potential to address depleting crude oil sources. The purpose of this study is to use Response Surface Methodology (RSM) to optimise bio-bitumen characteristics for sustainable pavements. Bio-bitumen is produced by combining conventional bitumen with biochar, cashew nutshell liquid, waste engine oil, and phthalic anhydride. This study uses RSM to investigate how these components (biochar, cashew nutshell liquid, waste engine oil, and phthalic anhydride) influence important bio-bitumen properties (penetration, ductility, softening point, and elastic recovery). A 2^4 factorial design with 27 trials was employed to optimise the mixing procedure. Statistical analysis, employing visualizations like contour plots and surface plots revealed an optimum bio-bitumen combination having 15% biochar, 1.71% cashew nutshell liquid, 0% waste engine oil, and a phthalic anhydride concentration ranging from 4.54% to 7.5%. This study illustrates the efficacy of RSM in optimising bio-bitumen for sustainable pavements, paving the way for more environmentally friendly road construction.

The effect of composite curing agent ratio on the photooxidative aging behavior of epoxy asphalt based on molecular dynamics simulation

In order to explore the effect of composite curing agent ratio on the photooxidative aging behavior of epoxy asphalt with an acidic composite curing system, three curing agent ratios of epoxy asphalt were prepared to obtain different cross-linking network densities. The prepared epoxy asphalt was subjected to photooxidation aging for 240 h at 60 ℃. Fourier transform infrared (FTIR) and elemental analysis tests were conducted to determine the evolution of chemical components during photooxidative aging. Based on the chemical components before and after aging, molecular models of photooxidation aged epoxy asphalt with different curing agent ratios were constructed. The mean square displacement (MSD) of oxygen atoms and the oxygen uptake of each component were calculated to study the diffusion behavior of oxygen atoms and the oxidation degree of each component under various cross-linking networks. Glass transition temperature (Tg) and interaction energy were determined to characterize the thermodynamic properties and interaction between asphalt phase and epoxy resin phase of epoxy asphalt before and after aging. The radial distribution function (RDF) was determined to simulate the distribution of asphaltene and epoxy resin crosslinked networks in different cross-linking networks. The results show that the formation of carbonyl groups, alcohol hydroxyl groups, and the fracture of methylene groups was observed during the photooxidative aging process of epoxy asphalt. The rise in the proportion of anhydride curing agents improved the stability of the chemical components in epoxy asphalt under photooxidation aging. High cross-linking density and methylene fracture weakened the diffusion ability of oxygen atoms in epoxy asphalt due to a reduction in free volume. In addition, photooxidation aging had a negative impact on the low-temperature performance and interaction between asphalt phase and epoxy resin phase of epoxy asphalt. However, a high content of acid anhydride alleviated the damage of photooxidation aging to low-temperature performance. Photooxidation aging developed the polar functional groups of epoxy asphalt, promoting the stacking of asphaltene under a high content of dicarboxylic acid curing agent, while breaking the stacking of asphaltene under a high content of acid anhydride curing agent.

The Design, Synthesis, and Characterization of Epoxy Vitrimers with Enhanced Glass Transition Temperatures.

A series of epoxy vitrimers (EVs) with enhanced glass transition temperatures (Tgs) were synthesized by curing epoxy resin E51 with different ratios of phthalic anhydride and sebacic acid as curing agents, and 1,5,7-triazabicyclic [4.4.0] dece-5-ene as a transesterification catalyst, and their curing dynamics, rheological properties, mechanical properties, and thermal stability were comprehensively investigated. By adjusting the molar ratio of the anhydride to the carboxylic acid in the curing agent, the Tgs of the EVs increased from 79 to 143 °C with the increase in the anhydride content. In particular, the material EV-5.5 with a high usable Tg of 98 °C could undergo stress relaxation through the transesterification reaction when exposed to high temperatures (160 to 200 °C), and the correlation between the relaxation time and temperature follows the Arrhenius equation. Moreover, EV-5.5 exhibited elastomeric behavior, where brittle fractures occurred before yielding, which demonstrated a tensile strength of 52 MPa. EV-5.5 also exhibited good thermal stability with a decomposition temperature (Td5) of 322 °C. This study introduces new possibilities for practical applications of thermoset epoxy resins under special environmental conditions.

Porous rod-like Co(OH)F/Co3O4 heterojunction-based acetic anhydride gas sensor with high response and low operating temperature

In response to the pressing demand for acetic anhydride gas detection, this study introduces a novel gas sensor for precisely detecting acetic anhydride concentrations. The optimum conditions for the synthesis of cobalt hydroxyfluoride/cobalt oxide (CHFCO) heterojunctions with good acetic anhydride gas sensitivity were determined by carefully adjusting the calcination time, hydrothermal time and ammonium fluoride content. The best performing composite CHFCO sensor with porous rod particles was tested at 180 ℃ and achieved a response rate of 260 for 100 ppm acetic anhydride gas, with response and recovery times of 60 and 40 s, respectively. In comparison to other prepared sensors, the detection response for acetic anhydride was improved by a factor of 4.30–23.63. Moreover, the CHFCO sensor reliably detected acetic anhydride at a concentration of 500 ppb, exhibiting a response value of 1.56. Notably, the sensor demonstrated great selectivity, moisture resistance, and stability. The findings highlight the significant enhancements in gas-sensitive performance to acetic anhydride achieved by the abundant hydroxyl bonds on the surface of CHFCO heterojunction, the presence of fluorine ions, and the modulation of the band gap. These results provide valuable insights for the advancement of acetic anhydride gas sensors based on CHFCO heterojunction.

Effect of Rice Husk and Wood Flour on the Structural, Mechanical, and Fire-Retardant Characteristics of Recycled High-Density Polyethylene.

Given the rising consumption of plastic products, it is becoming imperative to prioritize the recycling of plastic items as a solution to reducing plastic waste and environmental pollution. In this context, this research focuses on assessing the impact of incorporating rice husk and wood flour into recycled high-density polyethylene (rec-HDPE) to analyze its mechanical properties, flammability, and thermal stability. The combined rec-HDPE content of wood flour and rice husk varied between 0% and 20%. The rec-HDPE content of maleic anhydride grafted polyethylene (MAPE) was fixed at 3%. Mechanical characteristics such as flexural, tensile, and impact strengths were assessed. Cone calorimetry (CC) tests, limited oxygen index (LOI) tests, and horizontal and vertical burning tests were performed to determine the flammability or fire retardancy of these composites. On the other hand, to characterize the thermal characteristics of these composites, thermogravimetric analysis (TGA) was used. To further characterize the fluctuation in these characteristics, scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) studies were carried out. The mechanical characteristics were found to be increased in response to adding rice husk or wood flour. An 8% increase in tensile strength and a 20% increase in elastic modulus enhancement were recorded for a 20% rice husk-added composite. SEM revealed the reason for the variation in tensile properties, based on the extent of agglomeration and the extent of uniform distribution of fillers in rec-HDPE. Following these lines, the 20% rice husk-added composite also showed a maximum increase of around 6% in its flexural strength and a maximum increase of 50% in its flexural modulus. A decrease in impact strength was recorded for rice husk and wood flour-reinforced composites, compared with unreinforced rec-HDPE. Hybrid composites displayed a lack of mechanical strength due to changes in their nature. FTIR tests were performed for a much more elaborate analysis to confirm these results. Twenty percent of rice husk-added rec-HDPE displayed the best thermal properties that were tested, based on TGA and derivative thermogravimetric (DTG) analysis. This 20% composite also displayed the best fire-retardancy characteristics according to UL 94 tests, cone calorimetry tests, and limited oxygen index tests, due to the barrier created by the silica protective layer. These tests demonstrated that the incorporation of both fillers-rice husk and wood flour-effectively enhanced the thermal, mechanical, and fire-retardant attributes of recycled HDPE.