Unsaturated Polyester Composites Research Articles

Optimization, Sodium Hydroxide and Plantain Fibres: Mechanical Properties of Unsaturated Polyester Composites for Transtibial Prosthetic Socket

Low mechanical behaviors of natural fibres in the reinforcement of polymer composites have remain an issue of concern. This study is aimed at investigating the effect of NaOH treatment on the mechanical properties of plantain fiber for the transtibial prosthetic sockets made of polyester resin. Plantain fiber was extracted from the plantain bast using water retting techniques. The fibres were modified using alkaline treatment method of 5 – 25% for variable time of 30 to 150 minutes. It was optimized using 3-level Factorial design (3-LCD) of response surface methodology based on tensile properties of treated fibres. The polyester composites of plantain and glass fibers were prepared using hand-layup techniques. Instron Universal testing machine-3369 model was used to determine the tensile and impact properties of fibers and polyester composites. Rockwell hardness tester-RBHT/S-39 model was used to determine the hardness property. The optimum process conditions of 5 % NaOH for 119 minutes improved plantain fiber tensile strength, modulus, strain, energy, and extension by improved by 102.03, 208.07, 9.70, 210.52 and 205.73 %, respectively. The ultimate tensile strength and modulus was obtained at 10 and 12.5% fiber loading. The hardness and impact strength of NaOH modified unsaturated polyester composites was marginally more than 3.51 and 10.69% of glass fiber reinforced unsaturated composites, respectively, at 12.5% fiber loading. FTIR analysis revealed the improvement in mechanical properties. Thus, NaOH modified plantain fiber unsaturated polyester composites serves as a better alternative for making transtibial prosthetic socket.

Hybridization of woven kenaf and unidirectional glass fibre roving for unsaturated polyester composite

Hybridization of woven kenaf and unidirectional glass fibre roving for unsaturated polyester composite

The Compressive Strength of Unsaturated polyester reinforced by natural and synthetic Calcium Carbonate

A modifications on the ultimate compression strength of unsaturated polyester (UPE) carrying out, by adding nano Chicken eggshells fibers (E.S) as a natural source of calcium carbonate or synthetic nano calcium carbonate particles (CaCO3) in different weight percentages ranging from (1-5%). The ratio (1% eggshell fibers) and (3% CaCO3) are the best weight ratios that selected according to ultimate compressive strength of Unsaturated Polyester composites. Ultamite compressive strength was improved from (73.84 N/mm2) for UPE to (85.54 N/mm2) for (UPE/1% E.S) composite and to higher value (87.88 N/mm2) for (UPE/3%CaCO3) composite. The partictes with nano-sized of titanium dioxide (TiO2) was used to reinforce the two best composites, to get more improvement in there ultamite compressive strength to reach to (94.27 N/mm2) for (UPE/1%E.S) and to (100.18 N/mm2) for (UPE/3%CaCO3) composites.

Mechanical, wear, hydrophobic, and thermal behavior of waste cassava root cellulose and twill-weaved banana fiber-reinforced unsaturated polyester composites

Mechanical, wear, hydrophobic, and thermal behavior of waste cassava root cellulose and twill-weaved banana fiber-reinforced unsaturated polyester composites

Investigating the Influence of Stacking Sequences on the Physical and Mechanical Characteristics of Coconut Coir Fiber-Reinforced Unsaturated Polyester Composites

Investigating the Influence of Stacking Sequences on the Physical and Mechanical Characteristics of Coconut Coir Fiber-Reinforced Unsaturated Polyester Composites

Analysis of the strength of joints in fabric/ unsaturated polyester composites

Fabric/unsaturated polyester composites have garnered significant attention due to their lightweight properties and superior mechanical characteristics. Despite these advantages, the strength of joints within these composites remains a crucial aspect requiring thorough investigation. This paper presents a study focused on comprehending the factors that influence joint strength in fabric/polymer composites, emphasizing the importance of effective load transfer and robust adhesion within the fabric/polymer matrix. The objective is to minimize stress concentration and enhance load distribution within the joint. The failure mechanism involves a combination of Bearing Failure and shear-out failure, particularly in single-fabric layer composites. The study establishes a linear relationship between composite bending stiffness and the enforcement fabric’s flexural rigidity. A comparison of tensile properties across various joining methods, such as bolts, adhesive bonding, and tongue grooves, reveals that bolt joints exhibit the highest strength and elongation, followed by tongue groove joints. Notably, bolt joints demonstrate elevated toughness, efficiency, and stiffness in samples of two-layer twill fabric when the twill lines are oriented perpendicular to each other. Under these conditions, joint properties are measured at 0.89%, 14804.65 Nm, and 20.46 J, respectively. Increased fabric flexural rigidity yields advantages in terms of load distribution, load transfer efficiency, and dimensional stability. This study deepens the understanding of factors influencing joint strength, contributing valuable insights for the development of optimized joint designs and manufacturing processes. These advancements aim to enhance the performance and reliability of fabric/unsaturated polyester composites in applications requiring high strength and structural integrity.

Thermal and Mechanical Performances of Unsaturated Polyester Composites Reinforced by Natural Fillers

Thermal and Mechanical Performances of Unsaturated Polyester Composites Reinforced by Natural Fillers

Influence of Inner Gas Curing Technique on the Development of Thermoplastic Nanocomposite Reinforcement.

In this work, a comprehensive shrinkage and tensile strength characterization of unsaturated polyester (UPE-8340) and vinyl ester (VE-922) epoxy matrices and composites reinforced with multiwall carbon nanotubes (MWCNTs) was conducted. The aspect ratio of UPE and VE with methyl ethyl ketone peroxide (MEKP) was kept at 1:16.6; however, the weight of the MWCNTs was varied from 0.03 to 0.3 gm for the doping of the reinforced nanocomposites. Using a dumbbell-shaped mold, samples of the epoxy matrix without MWCNTs and with reinforced UPE/MWCNT and VE/MWCNT nanocomposites were made. The samples were then cured in a typical ambient chamber with air and an inner gas (carbon dioxide). The effect of the MWCNTs on UPE- and VE-reinforced composites was studied by observing the curing kinetics, shrinkage, and tensile properties, as well as the surface free energy of each reinforced sample in confined saline water. The CO2 curing results reveal that the absence of O2 shows a significantly lower shrinkage rate and higher tensile strength and flexural modulus of UPE- and VE-reinforced nanocomposite samples compared with air-cured reinforced nanocomposites. The construction that was air- and CO2-cured produced results in the shape of a dumbbell, and a flawless surface was seen. The results also show that smaller quantities of MWCNTs made the UPET- and VE-reinforced nanocomposites more stable when they were absorbed and adsorbed in concentrated salt water. Perhaps, compared to air-cured nanocomposites, CO2-cured UPE and VE nanocomposites were better at reducing shrinkage, having important mechanical properties, absorbing water, and being resistant to seawater.

Effect of fiber surface treatment on mechanical, interfacial, and moisture absorption properties of cattail fiber‐reinforced composites

AbstractSurface treatment of cattail, a lignocellulosic renewable fiber, was investigated to determine the conditions that would reduce moisture absorption while maximizing the properties of cattail fiber‐reinforced unsaturated polyester composites. Surface modification of cattail fiber was studied by treating them with 2.5, 5, and 10% of 1,6‐diisocyanatohexane (DIH) and 2‐hydroxyethyl acrylate (HEA) for three different immersion times (10, 20, and 30 min). DIH‐HEA treated fibers were preformed into a non‐woven mat and impregnated with unsaturated polyester resin to manufacture composite. The existence of covalent bonds on the treated fibers via NH and CN groups was confirmed by FTIR spectroscopy. The 10% DIH‐HEA resulted in the best results; while the mean diameter of the treated fiber decreased by ~37%, the modulus and the strength of it increased by ~267 and ~151%, respectively. Equilibrium moisture regain of the treated fibers and their composites decreased by ~43% and ~40%, respectively. The tensile modulus of the composites increased by ~171%. Enhancement in tensile strength is observed but could not be quantified due to the difference in Vf and scatter in the data. SEM examination confirmed the enhancement in fiber–matrix bonding due to surface treatment.

Study on Increasing the Cracking Resistance of Unsaturated Polyester Composites with MMA and Rice Husk Fiber Reinforcement

Study on Increasing the Cracking Resistance of Unsaturated Polyester Composites with MMA and Rice Husk Fiber Reinforcement

Alkali-treated date palm fiber-reinforced unsaturated polyester composites: thermo-mechanical performances and structural applications

Alkali-treated date palm fiber-reinforced unsaturated polyester composites: thermo-mechanical performances and structural applications

Effect of zinc oxide surface treatment concentration and nanofiller loading on the flexural properties of unsaturated polyester/kenaf nanocomposites

Due to environmental concerns and budgetary constraints associated with synthetic fibers, natural fibers (NFr) are becoming increasingly popular as reinforcement in polymer composites (PCs) for structural components and construction materials. The surface treatment (ST) method is a well-established technique for enhancing the strength of interfacial bonding between NFr and the polymer matrix (PM). As a result, this research aims to determine the effect of ST with zinc oxide nanoparticles (ZnONPs) on the flexural properties of unsaturated polyester (UPE)/kenaf fiber (KF) nanocomposites. The hand lay-up technique was employed to produce KF-reinforced unsaturated polyester composites (KF/UPE) for this investigation. UPE/KF-ZnONPs composites were made with varying NFr loadings (weight percent), ranging from 10 to 40%. KF was treated with five distinct amounts of ZnONPs (from 1 to 5% weight percent). According to the findings of the investigation, the composite samples incorporating ZnONPs displayed superior optimum flexural properties compared to the untreated KF composite. It was found that 2% ZnONPs was optimal, and ST with ZnONPs could produce robust KF with improved flexural properties.

Effect of alkaline treatment time of fibers and microcrystalline cellulose addition on mechanical properties of unsaturated polyester composites reinforced by cantala fibers

Abstract The aim of this study is to investigate the effect of alkaline treatment and addition of microcrystalline cellulose (MCC) on the density, tensile strength, elastic modulus, impact strength, and Poisson’s ratio of unsaturated polyester resin composites reinforced by cantala fibers (UPR-CFs). The fibers were immersed in alkaline solution of 6% NaOH for 0, 3, 6, 9, and 12 h. The composite had cantala fibers (CFs) and MCC volume fraction (v f) of 30 and 5%, respectively. The results showed that the alkaline treatment for 6 h resulted in the highest density, tensile strength, and elastic modulus of the composites, while the highest Poisson’s ratio was achieved in UPR-untreated CF composites. The addition of MCC filler also increased the density, tensile strength, and elastic modulus of the composite significantly. Both alkaline treatment and MCC addition did not significantly affect the impact strength. With the increase in the strength and modulus of elasticity, composites can be applied more widely to structures that bear higher loads.

Comparative analysis of hydrothermal properties of ramie fiber‐reinforced phenolic resin and ramie fiber‐reinforced unsaturated polyester composites

AbstractRamie fiber‐reinforced polymer (RFRP) composites are widely used in various fields owing to their environmental friendliness and cost efficiency. To understand the influence of different resin matrices on the mechanical properties and durability of RFRP composites under the same conditions and obtain better performance, ramie fiber‐reinforced phenolic resin (RFRPR) composites and ramie fiber‐reinforced unsaturated polyester (RFRUP) composites produced through compression molding were studied under hydrothermal conditions of 60°C with 50%, 85%, and 98% relative humidity for 3 months. The water absorption, tensile, flexural, and short‐beam shear properties were studied. The RFRPR composite had better flexural strength and short‐beam strength than the RFRUP composite. The saturated water absorption, water molecule diffusion coefficient, and retention rate of the RFRUP composite were higher than those of the RFRPR composite owing to the difference in the interfacial adhesion properties. The erosion of water molecules led to serious deterioration in the interfacial bonding performance of the RFRPR composite. It was found that the greater the humidity, the greater was the degree of interfacial degradation. This study lays the foundation for the further promotion and application of RFRP composites.

Experimental investigations of physical and mechanical properties of pineapple leaf/carbon fiber–reinforced unsaturated polyester composites at liquid nitrogen environment

Experimental investigations of physical and mechanical properties of pineapple leaf/carbon fiber–reinforced unsaturated polyester composites at liquid nitrogen environment

Effect of Pistachio Husks Powder Additive on Unsaturated Polyester Composites

In this study, polyester composites reinforced with pistachio shells powder (P.) with an averagediameter (150 – 200 μm) with different weight ratios (0.5%, 1%, 1.5%, 2%, and 2.5%) wereprepared to the resin. The Shore D hardness, thermal conductivity (K), and the glass transitiontemperature (Tg) of the samples were examined. The results showed that the Shore D hardnessincreases with the increase of the reinforcement ratio and its maximum value is (87.55) at (2.5%P.) While the value of hardness at (0%) is (86.5). The thermal conductivity increases slightly withthe increase in the percentage of reinforcement and its maximum value is (0.213253 W/ m. K) at(2.5% P.), while the value of K at (0% P.) is (0.170264W/ m. K), but with this slight increase inthermal conductivity, polyester composites remain from the insulating materials. The minimum(Tg) of (UPE/ P.) composites was the value (113.898°C) at (2.5% P.). Polyester composites areused in wood paints, either in primitive finishes or final finishes.

Layup optimization of ramie fabric reinforced composite: Woven fabric and lamination parameters

Composites reinforced with plant-based fabrics are gaining attention as promising, low cost and environmentally friendly alternatives to those reinforced with traditional synthetic fabrics. The present article studies the resin permeability and resulting mechanical properties of ramie fabric reinforced unsaturated polyester composites. First, the effects of the fabric areal density on the properties of composites were investigated and optimized. Then, composites were prepared with the fabric with the optimum areal density and varying lamination parameters including the number of fabric layers and the orientation of the fabric layers relative to the resin flow direction. The results showed that composites prepared with a fabric with an areal density of 135 g/cm2 had the highest resin permeability, tensile strength, tensile modulus, flexural strength, flexural modulus, and storage modulus due to high apparent porosity of the fabric reinforcement and efficient load-bearing structure of the composite. The optimal number of layers was determined to be 8, and because of the lower crimping in the weft compared with the warp of the fabric, layering the weft of the fabric at 90° relative to the resin flow direction increased the mechanical properties of the composites. Meanwhile, the composite with 8 layers of 135 g/cm2 fabric that were orientated 45° relative to the resin flow direction absorbed the most energy and had the highest impact resistance. In summary, the results presented here provide new selection guidelines to optimize the structure of laminated composites for various applications.

Thermally reduced sugarcane bagasse carbon quantum dots and in-plane flax fiber unsaturated polyester composites: surface conductivity and mechanical properties

Thermally reduced sugarcane bagasse carbon quantum dots and in-plane flax fiber unsaturated polyester composites: surface conductivity and mechanical properties

Experimental and Numerical Investigations on the Tensile Behaviour of Bamboo-Glass Fibres Hybrid Reinforced Polymer Composites

The paper presents the experimental and numerical investigations of the tensile properties of bamboo-glass fibres hybrid reinforced unsaturated polyester composites. The stacking configuration was GGBBBGG and GBGBGBG, with G and B, respectively denoted BFRP and GFRP. The hybrid composites were manufactured using a resin infusion technique. It was found that the tensile strength of the GGBBBGG was higher than that of GBGBGBG, but the elastic modulus seemed not significantly different. Hence, the glass fibres positioned at the outer layer (as skin of a sandwich composite) gave the better tensile properties than that of the alternating configuration. Numerical work utilising an extended finite element method (XFEM) had been undertaken, and a reasonable agreement on the failure load was found between the numerical and experimental results. However, the numerical load-displacement curves were underpredicted, which might be due to the load train of the testing equipment and also, the model did not include delamination within the layers.

Manihot esculenta tuber microcrystalline cellulose and woven bamboo fiber-reinforced unsaturated polyester composites: mechanical, hydrophobic and wear behavior

In this research Manihot esculenta (cassava) tuber stem microcrystalline cellulose (MCC) and woven bamboo fiber (WBF) reinforced unsaturated polyester (UP) composites are prepared and tested. The main aim of this study was to synthesis the microcrystalline cellulose from Manihot esculenta tuber stem and investigate the mechanical, wear and hydrophobic properties of UP resin composite made using MCC and WBF. The laminated composites were prepared by the hand layup method and characterized according to ASTM standards. According to the results, the composite containing 40 vol% of WBF increased the tensile strength and modulus, flexural strength and modulus, interlaminar shear strength, Izod impact as well as hardness by 39%, 10%, 42%, 27%, 1%, 91%, and 1%, respectively as compare to pure polyester resin composites. In comparison to all composites, the composite with 4 vol% of MCC exhibits the lowest sp. wear rate of 0.011 mm3/Nm. The water absorption contact angle indicated that all composite designations had a wider contact angle of more than 70°, which indicates a stronger hydrophobicity of composites. The SEM fractography reveals improved bonding and toughness for 4 vol% of MCC and WBF reinforced UP composites. Such mechanically stronger, wear resistance, as well as high hydrophobic composites, could be used in aerospace, automobile, defence and industrial sector.