Materials Science Forum Vol. 1189

Abstract: This article focused on the effect of natural materials on the Mechanical and Physical Properties of Polymer nanocomposite. Fibers and powder underwent treated with an alkaline solution to improve interfacial adhesion. were constructed with the hand lay-up technique with a PMMA/Epoxy blend and natural powders of egg shells and cuttle bone as reinforcements for medical applications in prosthetic arm fabrication. Therefore the cost of raw materials chosen must be important (i.e. economical and cheap for low-income amputees). Consequently, a prosthesis should be comfortable to wear, simple to put on and take off, light weight, long - lasting, and pleasing to the eye in terms of appearance. The polymer mix composition consisted of 25% PMMA and 75% epoxy, together with three distinct concentrations of natural powders (1, 2, and 3 wt.%) relative to the overall composite weight. The cured resin specimen was evaluated for mechanical and physical parameters, including impact strength, flexural strength, hardness, and density. The results demonstrated that the polymer nanocomposite sample achieved peak impact strength values of 12.2 KJ/m² for cuttle bone and 19.48 KJ/m² for eggshell. The flexural strength recorded was 73 MPa for cuttle bone and 71.2 MPa for eggshell, while hardness values were 83.6 for cuttle bone and 83.8 for eggshell at a 3% nanocomposite ratio. Conversely, the other tests of polymer blends (PMMA + Epoxy) using natural fibers (Siwak and flax) attained the highest results. The impact strength of specimens reinforced with siwak fibers significantly exceeds that of specimens reinforced with flax fibers, with flexural strength and hardness of 13.45 KJ/m², 70.6 MPa, and 86.5 shore D, respectively, compared to the base material (PMMA+EP). The density test results demonstrated an elevation in density corresponding to the increasing weight fraction of nanoparticles (eggshell and cuttle bone) in relation to the base material (PMMA+EP). Therefore, these samples may be considered suitable candidates for use as matrix materials that meet the requirements for prosthetic manufacture.

Abstract: Reactive structural material (RSM) has been used in modern warheads, binders in which has limitations in achieving high energy release and excellent mechanical properties. Epoxy resins, with their high oxygen content and good mechanical strength, show great potential as alternatives to traditional binders. In this work, two cured epoxy systems with different oxygen contents were prepared and tested under simulated explosion conditions. During detonation, combustion of resin fragments was observed, resulting in a peak blast pressure about 1.7 times higher than that of the bare explosive. Additional dispersion and combustion tests on resin powders confirmed that a higher oxygen content and more C-O bonds led to faster combustion and stronger pressure output. These results suggest that increasing the oxygen-rich structure of epoxy resins can effectively enhance both the combustion behavior and energy release, offering a new approach for developing high-performance binders in reactive materials.

Abstract: Composite based waste lignocellulose with matrix Polypropylene (PP) is a potential material tall For application friendly environment in the sector automotive, construction, and products technique sustainable. However , the differences polarity between PP matrix which is hydrophobic and fiber lignocellulose which is hydrophilic cause problem adhesion weak interface , which results in low characteristic mechanics and stability morphology composite . Maleic Anhydride Grafted Polypropylene (MAPP) has Lots used as agent clutch (compatibilizer) for overcome incompatibility said . Article This serve review comprehensive to mechanism MAPP's work in increase interaction matrix – reinforcement in composites based waste lignocellulose . The study was conducted to various five years of primary literature last to report results experiment about characterization chemical, mechanical, thermal, and morphological from reinforced PP–MAPP composite fiber lignocellulose. MAPP works through reaction esterification between group anhydrides and groups hydroxyl on the surface fiber , forming bond covalent bonding that increases adhesion interface and allows efficient voltage transfer . The addition of MAPP in range of 2–5% proven increase strength tensile strength , modulus of elasticity , and resilience thermal. In addition that , MAPP also plays a role in repair distribution fiber and reduce defect structural . With Thus, MAPP plays role key in increase performance composite waste lignocellulose PP matrix, as well as become approach strategic For support green material development and economy circular.

Abstract: Natural fiber-based composites are increasingly used in engineering applications due to their superior performance in producing lightweight, strong, and environmentally friendly materials. This study compares hot-pressed resin composites reinforced with teak sawdust become Teak sawdust Reinforced-Hot Pressed Resin Composite (TSR-HPRC) and coconut fiber became Reinforced Hot Pressed Resin CompositeCoconut coir Reinforced (CCR-HPRC). Teak sawdust is a wood industry waste with high strength and aesthetic value, while coconut fiber comes from coir and is abundant in tropical regions. Both are used as reinforcements for composite resins to improve mechanical properties. Through the hot-pressing method, this study evaluated the tensile strength, hardness, and coefficient of friction of TSR-HPRC and CCR-HPRC. Thorough testing was carried out, including statistical analysis (ANOVA) to determine the optimal reinforcement conditions. The results showed that TSR-HPRC had the highest tensile strength of 22.78 MPa and Shore D hardness of 80.87, superior to CCR-HPRC which only achieved 10.48 MPa and hardness of 76.55. The friction coefficient of TSR-HPRC ranges from 0.25–0.33, while that of CCR-HPRC ranges from 0.17–0.24. This study supports the development of cost-effective and sustainable composite materials, reducing dependence on synthetic fibers.

Abstract: Glass fiber-reinforced composites (GFRC) are widely used in structural applications due to their high strength-to-weight ratio and excellent fatigue resistance. Nevertheless, the mechanical integrity of adhesive joints remains a critical challenge in composite structural engineering. This study aims to investigate the influence of varying epoxy resin mixing ratios on the lap shear strength of glass fiber-reinforced composite joints. Two experimental schemes were conducted by varying the resin-to-hardener composition in the range of 10:50 to 70:50 (by weight). Single-lap joint specimens were fabricated and tested in accordance with ASTM D5868-95. The results demonstrated that a resin-to-hardener ratio of 50:50 yielded the maximum lap shear strength, reaching 5.71 MPa for resin system A and 5.28 MPa for resin system B. This ratio indicated a stoichiometric balance between epoxy groups and active amine groups, resulting in optimal curing with maximum cross-linking density. Deviations from this optimal ratio, either due to excess or deficiency of one component, led to a significant reduction in joint strength, as indicated by brittle fracture or weak adhesive bonding. These findings highlight the importance of precise control over epoxy adhesive formulations to ensure reliable mechanical performance in composite structures. The implications of this research contribute to the development of more durable and efficient adhesive systems, particularly for GFRC applications in the automotive, aerospace, and marine industries.

Abstract: This study aims to evaluate the antibacterial properties of dental resin photopolymer (DRP) specimens modified with additive titanium dioxide (TiO₂) nanoparticles using stereolithography 3D printing technology. TiO₂ known for its excellent biocompatibility, making it a promising additive for enhancing bacterial resistance. Specimens were fabricated with varying compositions of TiO₂ and characterized for surface morphology using Scanning Electron Microscopy (SEM). Antibacterial activity was assessed against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) using Kirby-Bauer disc diffusion method. SEM analysis revealed that TiO₂ particles were relatively well-dispersed on the matrix surface. Antibacterial testing showed the formation of inhibition zones, particularly in sample with composition 5%wt TiO₂, indicating increasing antibacterial performance. The activity was more pronounced against S. aureus, attributed to its less complex cell wall structure and more susceptible to reactive oxygen species (ROS) generated by TiO₂ photocatalytic conditions. These findings suggest that TiO₂-modified DRP has strong potential as an antimicrobial dental restorative material fabricated through SLA-based 3D printing.

Abstract: It has been studied how SiO₂ nanoparticles affect the mechanical and electrical properties of low-density polyethylene (LDPE). The tensile strength, microstructural features, and AC breakdown characteristics of LDPE containing silicon dioxide (SiO₂) nanoparticles were investigated in this work. The concentrations of filler were adjusted to 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 3.0 wt%, and 4.0 wt%. The samples were prepared by using Haake machine and shaped by compression moulding, and a sphere to sphere electrode arrangement was used for AC breakdown testing. The breakdown reliability was assessed using the Weibull distribution. Molecular interaction and nanoparticle dispersion were analysed using Raman spectroscopy and scanning electron microscopy (SEM), respectively. The findings demonstrated that mechanical strength and breakdown voltage increases with filler concentration, reaching a maximum at 2.0 wt% SiO₂. When compared to pure LDPE, the AC breakdown voltage increased by 27.54% at this concentration. SEM pictures showed a homogeneous dispersion of nanoparticles, while Raman spectra verified improved interfacial bonding. AC breakdown voltage above 2.0 wt% shows decrease value due to agglomeration of nanoparticles. According to this study, LDPE insulation performance is best enhanced by 2.0 wt% SiO₂.

Abstract: This study discusses the development of enhanced insulating materials for High Voltage Direct Current (HVDC) cable insulations by reinforcing Low-Density Polyethylene (LDPE) with nanomagnesia (MgO) particles. The main emphasis of this work is to investigate the DC breakdown voltage performance of LDPE/MgO nanocomposites as a function of filler content. Increase in DC breakdown strength is very important for long-term reliability and safety of HVDC cable insulation. Besides electrical performance, tensile strength and morphological study were made as complementary studies to check the mechanical stability and quality of particle dispersion. The nanocomposites were fabricated using the melt-blending method, where 40 grams of LDPE was mixed with 1.25 wt.%, 2.5 wt.% and 5wt.% of nanomagnesia at 170 [°C] and 50 rpm (rotation per minute) using a Haake internal mixer. The resulting materials were hot-pressed into 1 mm thin films at 160 [°C] and 50 bar pressure. DC breakdown voltage tests were conducted on the samples to determine their breakdown voltage. Tensile testing was conducted for the mechanical property evaluation where the LDPE and 2.5 wt% MgO composite show slightly lower strain, indicating decreased ductility. Overall, the incorporation of MgO enhances stiffness but reduces flexibility and strain-hardening capacity, resulting in a stronger yet less ductile material. Scanning Electron Microscopy (SEM) was undertaken to complement the results, which included the dispersion quality of MgO particles and the filler interfacial bonding. Results indicated that nanomagnesia incorporation improved the DC breakdown voltage of LDPE, with the optimum value at 2.5 wt.% of MgO. At this loading, the material showed the strongest dielectric strength while retaining reasonable tensile properties. Thus, this study has proven that LDPE reinforced with 2.5 wt.% of nanomagnesia is a viable and efficient insulation material for HVDC cable applications at average of 40.1 [kV] compared to pure LDPE at 32.41 [kV].

Abstract: Oral dispersible film (ODF) containing ascorbic acid (AA) was synthesised using the electrospinning process, and its dissolving behaviour was analysed by Ultraviolet-Visible (UV-Vis) spectroscopy. The obtained time, wavelength and absorbance data were applied to train an Artificial Neural Network (ANN) using the Levenberg-Marquardt algorithm. A total of 42 datasets were separated into training (90%), validation (5%) and testing (5%) sections. The ANN model displayed good predictive ability, giving a low mean squared error (MSE) and a regression coefficient (R=1), demonstrating a significant correlation between predicted and experimental dissolution profiles. These results demonstrate that ANN can efficiently predict ODF dissolution profiles, hence lowering experimental burden and boosting efficiency in pharmaceutical formulation research.