Epoxy Polymer Research Articles

A simple strategy to significantly improve the anticorrosion and aging resistance of epoxy coatings by adding polyaniline modified multi-walled carbon nanotubes

Epoxy coatings are widely used for corrosion protection of metals, but under extremely harsh environments, the epoxy polymer chains such as the C-O bonds of epoxy ether and aromatic ether, and the -OH in the epoxy chain structure can also undergo aging and degradation, leading to the failure of the coating in service. How to extend the anti-aging capability of epoxy resins while maintaining their other properties unchanged has become a major challenge in the practical application of epoxy coatings. In this study, the polyaniline (PANI) modified multi-walled carbon nanotubes (MWCNT@PANI) were synthesized by polymerization in-situ and added to epoxy resin as an anti-aging filler. The various measurements have been adopted to characterize the composition and structure of MWCNT@PANI, and the anticorrosive performance of the composite coating for carbon steel were evaluated via salt spray, chemical aging and UV light aging. Results showed that the impedance value of the blank epoxy coating decreases by at least two orders of magnitude after the salt spray tests, and the contact angle decreases by about 30° and gradually changes from hydrophobic to hydrophilic, indicating a significant decline in corrosion resistance. In contrast, the composite coating confirmed the excellent anti-aging performance, while the impedance values increased by approximately 2-5 orders of magnitude compared to that in blank epoxy coatings, and remained around 1010 Ω·cm2. Given the dense encapsulation of MWCNT@PANI, the dispersion stability between the filler and EP can be improved, and the effective corrosion resistance performance was also supported by molecular dynamic simulation. Besides that, the ability of free radical quenching along with the labyrinth effect and hydrophobic interaction have also been investigated to explain the anticorrosion and anti-aging mechanism.

Effect of tin oxide particle size on epoxy resin to form new composites against gamma radiation.

The aim of the present study is to assess the shielding performance of a novel lead-free epoxide material against ionizing radiation. The effect of variation in particle size and concentration of tin oxide (SnO), which was added to epoxy resin polymer (ER), on its radiation shielding properties has been investigated in this research. Ten samples of ER samples incorporated with different concentrations (0%,20%,40%,60%) of SnO microparticles, nanoparticles, and both sizes combined were prepared and assessed. The linear attenuation coefficients (LAC) were measured experimentally through the collimated gamma-ray beam at 0.0595MeV, 0.6617MeV, 1.1730MeV, and 1.330MeV emitted from Am-241, Cs-137 and Co-60, respectively (to cover all energy range of gamma rays) for all samples with various concentrations and particle sizes of SnO. The other radiological shielding parameters such as half value layer (HVL), tenth value layer (TVL), and radiation protection efficiency (RPE) were estimated and compared for all different samples. The results prove that the increasing of the concentration and reducing the particle size of SnO leads to the enhancement of the radiation protection properties of the ER polymer. Moreover, it was observed that the incorporation of SnO micro- and nanoparticles together improves the radiation shielding properties of ER samples. Conclusively, the reinforcing of ER polymer material matrix by micro/nanoparticles of SnO as composite with enhanced radiation shielding specifications was highlighted.

Investigation of Adsorption and Young’s Modulus of Epoxy Resin–Sand Interfaces Using Molecular Dynamics Simulation

Epoxy resins exhibit outstanding curability, durability, and environmental compatibility, rendering them extensively utilized in the realm of engineering curing. Nevertheless, the current curing mechanism of epoxy-based resins in cohesion with sand remains inadequately elucidated, significantly impeding their applicability within the domain of soil curing. This study employed molecular dynamics simulations to investigate the adsorption behavior of three distinct types of epoxy resins on the sand surface: diglycidyl ether of bisphenol-A epoxy resin (DGEBA), diglycidyl ether 4,4′-dihydroxy diphenyl sulfone (DGEDDS), and aliphatic epoxidation of olefin resin (AEOR). The objective was to gain insights into the interactions between the sand surface and the epoxy resin polymers. The results demonstrated that DGEDDS formed a higher number of hydrogen bonds on the sand surface, leading to stronger intermolecular interactions compared to the other two resins. Furthermore, the mechanical properties of the adsorbed models of the three epoxy resins with sand were found to be relatively similar. This similarity can be attributed to their comparable chemical structures. Finally, analysis of the radius of gyration for the adsorbed epoxy resins revealed that AEOR exhibited a rigid structure due to strong molecular interactions, while DGEDDS displayed a flexible structure owing to weaker interactions.

Regulation of Glass Transition Temperature in Thermo‐Responsive Epoxy Shape Memory Polymers: The Roles of Chemical Crosslinking Density and Chain Flexibility

ABSTRACTShape memory polymers (SMPs) are novel kinds of smart materials whose shape can be changed in external conditions such as heat stimulus. Due to their excellent structural versatility and high elastic strain, they have important applications in the field of biomaterials. Here, a series of amorphous shape memory polymer materials are prepared and their shape memory properties and glass transition temperature (Tg) are also investigated. A special kind of epoxy polymer, whose shape can be changed at around physiological temperature, is synthesized by regulating the crosslinking density and introducing flexible aliphatic epoxy chains. The shape memory function of this epoxy polymer is studied by deformation test. In addition, to explore their application in the field of biomedical materials, the biocompatibility of the materials are evaluated, including the effects on the erythrocyte hemolysis rate and cell activity. The experimental results show that this kind of epoxy polymer has good shape memory function and biocompatibility.

Impact of Graphene Nano particles on static and dynamic mechanical properties of basalt-glass fibre reinforced epoxy polymer hybrid composites

ABSTRACT This paper investigates the structure-property relationships in basalt – glass fabric reinforced hybrid polymer composites doped with graphene nanoplatelets. Basalt Glass fabrics were reinforced with 0.2 wt.% − 0.8 wt.% graphene using hand layup and compression moulding to fabricate laminated plates. The mechanical, morphological, and thermomechanical properties were characterised using tensile, flexural, impact, SEM, FTIR, XRD, and DMA testing. Results showed that low graphene loadings of 0.2 wt.% − 0.4 wt.% led to small, isolated graphene platelets decorating the basalt fibres. At 0.8 wt.% loading, extensive wrinkling, folding, and stacking of graphene sheets on the basalt was observed. FTIR revealed increasing sp2 C=C vibrations and XRD showed rising graphene peak intensities with higher loadings. While tensile and flexural strengths improved up to 0.6 wt.% graphene due to efficient stress transfer, impact energy increased consistently until 0.8 wt.% graphene owing to reinforcement effects. DMA exhibited enhanced storage modulus and restricted mobility with more graphene. An optimum graphene loading of 0.6 wt.% was found to maximise the mechanical performance through uniform dispersion and strong interfacial adhesion. The results demonstrate that graphene incorporation can substantially augment the strength, toughness, and thermomechanical properties of the composites at appropriate compositions prior to aggregation.

Effect of chemical treatments of fibre surface on mechanical properties and wear rate of Beerakaya (Luffa acutangula) reinforced epoxy polymer composites

Effect of chemical treatments of fibre surface on mechanical properties and wear rate of Beerakaya (Luffa acutangula) reinforced epoxy polymer composites

Experimental Research on the Possibility of Changing the Adhesion of Epoxy Glue to Concrete

Among the many methods of joining different materials, gluing is characterized by its most specific nature. In comparison with, for example, welded, screwed, or overlapped connections, a glued connection depends on the largest number of factors. Many of them are related to the phenomenon of adhesion, which is complicated by definition. It has many shapes and forms, and its existence determines not only the durability of such a joint but also the possibility of its execution. Epoxy polymers are among the most commonly used adhesives. Their extremely good parameters can be easily modified by additives in the form of fillers. Compatibility between the filler and the adhesive allows for further improving the adhesive parameters in the glued joint. However, in order to effectively combine the adhesive and the filler, different, often specific mixing methods must be used. The following study presents the results obtained in an experimental research program, the aim of which was to increase the adhesion of epoxy resin to a properly prepared concrete substrate. As a method to increase the final adhesion, the addition of microsilica and carbon nanotubes in an experimentally determined amount was selected. The use of sonication as a mixing method together with cavitation allowed for improving the parameters which determine the final adhesion of the adhesive to concrete. The parameters which were selected to describe the course of changes in the adhesion of the adhesive to the concrete substrate were the viscosity, free surface energy, surface parameters, adhesion, and SEM images of the tested resin in various modification configurations. The obtained results make it possible to form stronger and more durable adhesive joints during the reinforcement of concrete structural elements using fiber-reinforced polymer (FRP) composites.

Molecular Mechanism of Physical and Mechanical Improvement in Graphene/Graphene Oxide-Epoxy Composite Materials.

The performance provided by graphene (Gr) and graphene oxide (GO) additives can be improved by achieving strong adhesion and uniform dispersion in the epoxy resin matrix. In this study, molecular modeling and simulation of DGEBA/DETA based epoxy nanocomposites containing Gr and GO additives were performed. Density functional theory and molecular dynamics simulations were used to investigate interfacial interaction energies and Young's Modulus. Improvement in the interaction energies was studied by controlling the epoxy:hardener ratio, type and the number of oxygen-containing functional groups on the GO, the mass percentage of Gr/GO filler in the epoxy matrix, size and dispersion of GO in the cell. It was demonstrated that functional groups with up to 10 % oxygen content in GO significantly increase interfacial interaction energy for large size Gr/GO. Increasing DETA type amine ratio in the preparation of epoxy polymers increases the interaction energy for high oxygen content while decreasing the interaction energy for low oxygen content in GO for small size GO with edge functional groups. The performance of material dramatically decreased even at high DETA hardener and high GO mass percentages when the aggregation factor of Gr/GO was included in simulations that explain lower Gr/GO percentages in the experimental studies.

Synergistic effect by release of corrosion inhibitors via cellulose nanofibers in self-healing polymer coatings to prevent corrosion of carbon steel

To inhibit the corrosion of carbon steel, epoxy polymer coatings were developed using cellulose nanofibers (CNF) and the corrosion inhibitors sodium nitrate (SN) and sodium oleate (SO). The synergistic effects of SN and SO were confirmed by measuring the polarization curves of bare carbon steel in a corrosive solution, which demonstrated the effectiveness of a first action by SN being followed by a second action by SO. In order to control the release rates for the corrosion inhibitors from polymer coatings, the addition of CNF in the polymer was effective. The optimum combination of SN, SO and CNF in the polymer coatings was 8% of SN in the first layer, then 8 and 0.5% of SO and CNF, respectively, in the second layer, which resulted in excellent self-healing properties. The controlled release for the synergistic effect of the corrosion inhibitors allowed them to generate a healing film on the damaged portions of carbon steel

Performance analysis of uncoated and coated (TiN-, TiAlN-) carbide drills in drilling graphene-reinforced GF/epoxy nanocomposites: Analytical and experimental study

The present study aims to investigate the performance of conventional uncoated and coated (TiN, TiAlN) solid carbide drill tools in drilling bi-directional graphene-reinforced (2 wt.%) glass fiber (GF)/epoxy polymer nanocomposite laminate with two distinct lamination schemes ([0/90]12S and [0/90/±45]6S). Performance measures included thrust force, torque, tool flank wear, peak acoustic emission, root mean square (RMS) of acoustic energy, and average surface roughness. Moreover, the delamination that occurs beyond the critical value of thrust force (computed analytically) has also been addressed. Optimized drilling parameters were used for experimentation to minimize thrust force and torque simultaneously. Both TiN and TiAlN-coated carbide drills outperformed uncoated carbide drills for fewer holes (around 25 for TiN and about 40 for TiAlN), but their performance deteriorated with more holes due to coating chipping or peeling from the original tool material. The (0/90 ± 45)6S graphene-reinforced layup showed less tool wear, deterioration, and acoustic emission energy compared to the (0/90)12S neat layup. TiAlN-coated drills exhibited the smallest wear on the flank face followed by TiN-coated and uncoated carbide drills. Moreover, the smoothest cut surface throughout the 300 holes drilled, averaging 1.5 µm to 1.8 µm in surface roughness, was observed with the TiAlN-coated drill. Therefore, the TiAlN-coated drill is recommended for drilling a larger number of holes due to its reduced tool wear, smoother cut surfaces, and better form accuracy with minimal delamination.

Design and Modulation of Negative Thermal Expansion for Epoxy Polymers.

Modulating the coefficient of thermal expansion (CTE) and realizing low or negative thermal expansion (NTE) for epoxy polymers are challenging issues. In this study, we developed an effective strategy to prepare epoxy polymers with an NTE performance. A novel motif DBCOD-NH2 based on the dibenzocyclooctadiene (DBCOD) was designed, synthesized, and utilized as a curing agent for several commercial epoxy resins. DBCOD-NH2 suppressed the thermal expansion of the epoxy polymer due to the conformational transition of DBCOD from boat to chair, resulting in low or negative CTE. The AFG90-based polymer showed the most significant thermal contraction behavior (-43.6 ppm/K, 40-80 °C) in the glassy state due to the high DBCOD content, chain rigidity, and cross-link density, which resulted from the high epoxy values, rigidity, and functionality of AFG90 resins. The structure-property interactions were examined and applied to modulate the NTE of epoxy polymers. Our findings are useful for the regulation of thermal expansion and the preparation of materials with desired CTE values.

Novel hydrogen-bonded organic frameworks-based coating for fat oil and grease deposition control in the sewer system

Hydrogen-bonded organic frameworks (HOFs) represent an emerging class of porous materials characterized by crystalline frame structures, self-assembled from organic molecules through hydrogen bonding. This study demonstrates that HOFs fragment into small particles while preserving their original structure when dispersed in a polymeric epoxy solution. The intermolecular hydrogen bond structural and electronic properties of the LH4-HOF complex as well as the mechanism of HOF incorporated epoxy were extensively studied using density functional theory. LH4-HOF has a high Langmuir surface area of 2758.3 m2/g and nonlocal density functional theory pore size distributions of 3 A°. This unique solution processability enables the fabrication of coatings with high stability in aqueous systems. Results from a 30-day leaching test under controlled conditions (pH 7, temperature 20 ± 2 °C) indicate that LH4-HOF incorporated epoxy-coated concrete samples exhibited an over 85 % reduction in calcium release compared to uncoated samples, with epoxy-coated samples alone showing a 60 % reduction in calcium leaching. Additionally, the LH4-HOF-incorporated epoxy coating reduced the formation of fats, oils and grease deposits by more than 73 % on the concrete samples. Thus, this novel coating approach offers a sustainable solution with significant potential applications in sewer management.

Durability of epoxy and vinyl ester polymers in wet, seawater, and seawater sea sand concrete environments: Molecular dynamics simulations

Epoxy and vinyl ester (VE) deteriorate under harsh environmental conditions typical of marine and offshore applications. Enhancing their performance requires a deeper understanding of their molecular-level interactions with these environments. This study uses molecular dynamics simulations to investigate the behavior of epoxy and VE under dry, wet, Na2SO4, NaCl, NaOH, KOH, and simulated seawater sea sand concrete (SWSSC) pore solution environments. The effect of temperatures ranging from 300 K to 368 K was also explored. Key parameters, such as radial distribution function, hydrogen bond dynamics, diffusion coefficients of water molecules and ions, swelling ratio, and glass transition temperature (Tg), were analyzed. Results show that epoxy is more sensitive to environmental effects than VE. In the dry state, three types of hydrogen bonds (H-bonds) were identified, with 64 % of the hydroxyl (OH) group involved in epoxy and 34 % in VE. As temperature increases, polymer chain interactions weaken, leading to a decrease in H-bonds, with epoxy showing a faster decline. Absorbed water molecules accumulate near the polymer polar sites, particularly at the OH groups, breaking some polymer-polymer H-bonds and forming new ones with the polymer polar sites. The hydrogen atoms of most absorbed water molecules orient away from the OH group, creating binding sites for water clustering through water-water H-bonds, leading to plasticization and potential hydrolytic degradation. Ions increase the number of polymer-water H-bonds, significantly decreasing polymer-polymer H-bonds (by 59.22 % for epoxy and 51.52 % for VE in SWSSC), thus accelerating material deterioration. Free volume distribution and dynamics, the transition between bound and free water, hydrogen bond dynamics, as well as ion hydration and dehydration collectively influence the water diffusion process in the polymer networks. Ion species diffuse much slower than water molecules, with epoxy showing higher permeability to Cl- and OH- compared to VE. Glass transition temperature (Tg) of both polymers is sensitive to environmental exposure, with epoxy being more affected. The detrimental effect on Tg is ranked as SWSSC > KOH > NaOH > NaCl > Na2SO4 > Wet. These findings provide new nanoscale insights into the interactions between polymers and SWSSC environments, offering a foundation for accurately predicting the durability of polymer-reinforced SWSSC.

Synthesis of reaction promoters for epoxy polymerization: Enhancing storage stability and mechanical properties of one‐pot epoxy systems

AbstractOne‐pot epoxy formulations, containing uncured resin, curing agent, and promoter, require the promoter to be insoluble in the resin at room temperature to prevent premature polymerization. Here, we introduce three novel reaction promoters synthesized by reacting amino propyl imidazole (API) and various diisocyanates such as HMDI, IPDI, or MDI. We evaluate the impact of these promoters on the physical properties, storage stability, and curing kinetics of the resulting epoxy formulations. The results of the kinetic study showed that the compositions containing each synthesized promoter acted as reaction promoters, as evidenced by the lower activation energy in the differential scanning calorimetry (DSC) experiment. The results of the mechanical properties showed that HMDI‐API promoter improved both tensile and flexural strength, while exhibiting high storage stability. The findings provide valuable insights for selecting suitable promoters for specific applications in one‐pot epoxy systems.

The preparation of polyaniline/graphene/polypropylene nanocomposite and its novel antibacterial activity

AbstractThe demand for polymers with antibacterial properties is increasing in food packaging industry and medical supplies. Antibacterial additives without toxic metal ion release are crucial for health and safety but still have challenges. Herein, polypropylene (PP) nanocomposite was prepared with polyaniline/graphene nanocomposite (PANI/GNP) as a green antibacterial additive due to its electrostatic, free radical, and nanoknife effect synergistic antibacterial mechanisms. To improve the dispersibility of PANI/GNP, nanosilica coating on PANI/GNP was constructed successfully with in situ condensation polymerization of epoxy functionalized ethyl orthosilicate to obtain EP‐nSiO2‐PANI/GNP. EP‐nSiO2‐PANI/GNP with a thin nanosilica coating has a significantly improved thermal stability as compared with that of PANI/GNP characterized by TGA. The EP‐nSiO2‐PANI/GNP presents a nanoscale disperse state in PP nanocomposite and thus enhances the melt viscosity and storage modulus accordingly characterized by TEM and Rheology. The EP‐nSiO2‐PANI/GNP/PP filled with 0.5 wt% of EP‐nSiO2‐PANI/GNP demonstrates antibacterial activity of 100% against both Escherichia coli and Staphylococcus aureus.Highlights In situ condensation polymerization to prepare EP‐nSiO2‐PANI/GNP. EP‐nSiO2‐PANI/GNP has enhanced dispersion stability. EP‐nSiO2‐PANI/GNP with a thin nanosilica coating has a good thermal stability. PP nanocomposite with 0.5 wt% filler has excellent antibacterial activity. The electrostatic, free radical, and nanoknife effect antibacterial mechanism.

Impact performance of egg‐box core sandwich panels made from sisal fibers and castor‐oil‐based polymer

AbstractDeveloping sustainable composites for engineering applications is essential for minimizing environmental impacts and ensuring the long‐term viability of infrastructure and technological advancements. In this context, this work focuses on the manufacture and evaluation of the structural integrity of a sandwich structure composed of aluminum faces and egg‐box‐shaped, sisal fiber‐reinforced epoxy (SFE) or castor‐oil polyurethane (SFC‐O) composites. The sandwich panel is filled with a biobased foam and subjected to dynamic load (drop‐tower) test. For comparison, the base materials SFE and SFC‐O molded into the egg‐box‐shaped cores are also evaluated using Charpy impact tests to establish a potential correlation between their Charpy performance and the drop‐tower behavior of egg‐box sandwich structures. The findings reveal that SFC‐O laminates demonstrate superior Charpy impact resistance (~49%) compared to SFE laminates. Similarly, sandwich structures composed of egg‐box‐castor‐oil composite cores absorb approximately 42.5% more energy than those made with egg‐box‐epoxy cores. The impact behavior of the sandwich structures correlates directly with the impact resistance of the sisal fiber laminates. Overall, the results indicate that the castor‐oil polymer can effectively replace the epoxy polymer matrix phase, enhancing impact absorption and providing an environmentally correct and sustainable solution for fabricating sandwich panels.Highlights Castor‐oil polymer provides laminates with lower density relative to epoxy. Sisal‐castor‐oil‐based laminates possess higher impact resistance than those based on epoxy. Sisal‐castor‐oil‐based panels achieve higher absolute and specific drop‐tower impact properties. Panels subjected to drop‐tower impact tests reveal skin delamination, wrinkling and indentation. Debonding between the foam and egg‐box core is a typical failure mode for epoxy sandwich panels.

A generalized machine learning framework to estimate fatigue life across materials with minimal data

In this research, a generalized machine learning (ML) framework is proposed to estimate the fatigue life of epoxy polymers and additively manufactured AlSi10Mg alloy materials, leveraging their failure surface void characteristics. An extreme gradient boosting algorithm-based ML framework encompassing Synthetic Minority Over-sampling TEchnique (SMOTE), categorical data encoding, and external loop cross-validation is developed to evaluate the fatigue life across materials. The influence of different training strategies based on materials, input features, encoding method, and data standardization on the model performance is explored. Additionally, the importance of anti-data-leakage and anti-overfitting measures over the ML model performance is addressed. The result shows that the data-leakage-free, external loop cross-validated model can estimate the fatigue life of selective epoxy polymers and metal alloys with an average R2 of 0.71 ± 0.06 using a mere 12 to 27 experimental data points per material category. Whereas the model trained with data-leakage and overfitting results in high R2 of 0.9.

Physical, Mechanical and Thermal Characterization of Areca, Pineapple and Glass Fiber Reinforced Polymer Composites for Aerospace Applications

In the current scenario, the focus on applying natural fiber-reinforced polymer composites in aerospace applications has increased tremendously due to their attractive characteristics such as lightweight, higher strength-to-weight ratio, good thermal stability at environmental temperatures, resistance to corrosion, sound absorbing capability and increased fuel efficiency. Further, studies on Bi-directionally oriented fiber composites have more advantages than the random or unidirectional orientation, such as uniform stress distribution and improved bonding at the interface. So, the present work focuses on using the Areca, Pineapple Leaf Fiber (PALF) and Glass fiber as the bi-directional fiber mat for reinforcing it into Epoxy polymer. The three different materials were fabricated by changing the fiber type with constant volume fraction and orientation. The martial characterization was done on the fabricated composites in order to evaluate their orientation effectiveness through density, moisture absorption, tensile, impact, hardness and thermal degradation. The bonding relationship was analyzed through a Scanning Electron Microscope. The results showed that the properties obtained were higher for the PALF composite than the areca composites due to the fact that the higher surface area of PALF fibers is confirmed through SEM analysis.

Design and Characterization of Epoxy Resin Systems Based on Mixtures of Imidazolium-Based Ionic Liquids with Docusate and Dicyanamide Anions

This study focuses on the synthesis, characterization, and application of four ionic liquids (ILs), three of which are being reported for the first time, with unique thermal properties and diverse anion-cation combinations, specifically in the context of epoxy resin polymerization. 1-3-Didodecylimidazolium dicyanamide (dDDIM DCA), 1-3-Didodecylimidazolium docusate (dDDIM DOSS), 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA), and 1-ethyl-3-methylimidazolium docusate (EMIM DOSS) were used to prepare six different mixtures with the same cation and with varying concentrations of DCA components, which is the main factor of an efficient polymerization, while the other component is intended to modify the properties of the cured resin. Mixtures based on EMIM cation demonstrated increased enthalpy and lower onset polymerization temperatures, indicating more efficient curing processes. The hardness of cured epoxy resins can be adjusted by altering the curing temperature and IL composition, with EMIM DCA and EMIM DOSS mixtures displaying high Shore A hardness, suitable for durable surface applications. In contrast, mixtures with higher dDDIM DCA proportions offered a balance between rigidity and flexibility, ideal for applications requiring both mechanical strength and elasticity.

Electrical and dynamic mechanical analysis of kenaf fiber reinforced epoxy composites hybridized with acacia concinna powder

The objective of this work is to create and analyze composites made of kenaf fibers and epoxy polymer, which are strengthened by the addition of Acacia concinna pod (ACP) powder. These composites are intended for use in electrical insulation applications. The study investigated the impact of alkali treatment using a 6% NaOH solution on kenaf fiber. The effects were analyzed in relation to the dielectric and dynamic mechanical properties, while also considering the addition of different quantities of ACP powder (0%, 4%, and 8%). The composites were produced using the hand layup method, and the dielectric constant, dissipation factor, storage modulus, loss modulus, and damping factor were assessed. The study demonstrated that NaOH-treated kenaf fiber composites displayed considerably lower dielectric constant values than untreated composites, due to increased fiber crystallinity and decreased moisture absorption. Dynamic Mechanical Analysis (DMA) found that untreated composites had greater storage modulus and glass transition temperature (Tg) due to reduced segmental motion at the fiber-matrix interface. SEM research indicated better fiber-matrix bonding in treated composites, with decreased voids and robust interlocking, notably in those containing 4% Acacia concinna (ACP) filler. These findings show that NaOH treatment substantially enhances the performance of hybrid composites for electrical insulating applications.