Fiber-reinforced Unsaturated Polyester Research Articles

Hygrothermal Effect on GF/VE and GF/UP Composites: Durability Performance and Laboratory Assessment.

In order to investigate the durability of two kinds of fiber-reinforced composite materials, and obtain the degradation mechanism and failure model in a hygrothermal environment, E-glass- fiber-reinforced composite materials, glass fiber-reinforced epoxy vinyl ester and glass fiber-reinforced unsaturated polyester (named GF/VE and GF/UP, respectively) were chosen to suffer rigorous hygrothermal aging. Their mechanical performance was monitored during the aging process to evaluate their durability. The cause of deterioration of the composite was comprehensively analyzed. Based on the analysis results of attenuated total-reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA), the change mechanism of chain structure of the resin molecule was proposed. SEM (scanning electron microscopy), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to analyze the microstructure and degradation mechanism of the fiber and the interface between fiber and matrix. The degradation mechanism of the composite system, including the resin, the fiber and the interface, was obtained, and it was found that the deterioration of the matrix resin caused by the hygrothermal environment was the main factor leading to the decline in composites performance.

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

Characterization of peanut husk-derived Si3N4 basalt fiber-reinforced unsaturated polyester resin composites

Characterization of peanut husk-derived Si3N4 basalt fiber-reinforced unsaturated polyester resin 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

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

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.

Mechanical, thermal, and water absorption properties of hybrid short coconut tree primary flower leaf stalk fiber/glass fiber-reinforced unsaturated polyester composites for biomedical applications

Mechanical, thermal, and water absorption properties of hybrid short coconut tree primary flower leaf stalk fiber/glass fiber-reinforced unsaturated polyester composites for biomedical applications

Effect of Fibre Surface Treatment on the Mechanical Properties of Jute Fibre Reinforced Unsaturated Polyester Composite

ABSTRACT Interface between the fiber and polymer matrix plays a key role in fiber-reinforced composites. Modification of the interface by chemicals or particles promotes the interaction between fiber and matrix. In the present study, attempt has been made to modify the surface of jute fiber with starch particles, an eco-friendly and low-cost material. Coating of starch on jute fiber has been carried out by a solution-based approach with variation in fiber to starch ratio (100:1, 100:5, 100:10). Composites have been prepared by hand lay-up technique using starch uncoated and coated fibers along with unsaturated polyester resin (UPR). Fibers have been characterized by microscopy and thermal analysis which reveals the coating of starch particles on fibers. It has been observed that with increasing starch concentration roughness increases but higher content leads to smooth surface of the fiber. The mechanical properties of composite sheets have been evaluated by tensile, flexural and impact testing. Maximum tensile strength of 20.5 MPa and Young’s modulus of 1457.7 MPa has been obtained in composites having starch-coated fibers with fiber to starch ratio of 100:5. water absorption studies show marginal variation in water uptake by the composites with starch-coated jute fibers.

Effects of drilling parameters on delamination of kenaf-glass fibre reinforced unsaturated polyester composites

Drilling is a secondary material removal and usually carried out to facilitate fastening of parts together. Drilling of composite materials is not usually a problem-free process. Issues related to delamination composite laminates need to be addressed because it introduces the stress concentration point on the composite. This study focussed on the influence of process parameters such as spindle speed, feed rate, type of drill bits and geometry on the extend of delamination experienced by the composite during the drilling process of kenaf-glass fibre-reinforced unsaturated polyester composite, and the delamination measurements were taken under a microscope. Taguchi methods and analysis of variance were employed to find the optimal parameters. From the results, the most significant parameter was the feed rate. The minimum delamination was achieved when the feed rate was 0.05 mm/rev and spindle speed was 700r/min using both types of drill bits. The quality of the drill hole using the twist drill bit has been proven to be better than the brad drill bit.

High Mechanic Enhancement of Chopped Carbon Fiber Reinforced-Low-Density Unsaturated Polyester Resin Composite at Low Preparation Temperature with Facile Polymerization.

Chopped carbon fiber-reinforced low-density unsaturated polyester resin (CCFR-LDUPR) composite materials with light weight and high mechanical properties were prepared at low temperature and under the synergistic action of methyl ethyl ketone peroxide (MEKP-II) and cobalt naphthenate. Optimal preparation conditions were obtained through an orthogonal experiment, which were preparation temperature at 58.0 °C, 2.00 parts per hundred of resin (phr) of NH4HCO3, 4.00 phr of chopped carbon fibers (CCFs) in a length of 6.0 mm, 1.25 phr of initiator and 0.08 phr of cobalt naphthenate. CCFR-LDUPR composite sample presented its optimal properties for which the density (ρ) was 0.58 ± 0.02 g·cm−3 and the specific compressive strength (Ps) was 53.56 ± 0.83 MPa·g−1·cm3, which is 38.9% higher than that of chopped glass fiber-reinforced low-density unsaturated polyester resin (CGFR-LDUPR) composite materials. Synergistic effects of initiator and accelerator accelerated the specific polymerization of resin in facile preparation at low temperature. Unique “dimples”, “plate microstructure” and “surface defect” fabricated the specific microstructure of the matrix of CCFR-LDUPR composite samples, which was different from that of cured unsaturated polyester resin (UPR) with “body defect” or that of CGFR-LDUPR with coexistence of “surface defect” and “body defect”.

Mechanical Behaviour of Coconut Coir Fibre Reinforced Unsaturated Polyester Composite

With low cost, simplicity of manufacturing and the abundant availability of natural fibers have tempted the researchers to try the available fibres and to investigate their possibility of using it for the purpose of reinforcement. Since Coir fiber is renewable, eco-friendly, less weight and has good mechanical performance it is considered as one of the best alternative to Carbon fiber. In this present work the ability of coir fibre in improving the mechanical characteristic has been studied. Four specimens having different weight fractions (5%,10%,15% &20%) of coir fiber with polyester matrix is prepared and their corresponding mechanical properties has been determined. In this work the fiber is treated with Sodium Hydroxide (NaOH) for attaining good fiber separation and hand- lay-up practice have been employed for composite manufacturing. To find the mechanical characteristics of composite the following tests were performed on the prepared specimens like tensile test, Flexure and hardness test. Experimental result reveals that the composite with 15% coir fiber have a maximum tensile strength of 26.5Mpa From the Experimental results it is evident that the increase in coir fiber weight fraction results in improving the mechanical properties of the composite.

Effect of electron beam irradiation on mechanical properties of unsaturated polyester/nanoclay composites reinforced with carbon and glass fibers

Following our previous work on morphology, corrosion resistance and thermal properties of unsaturated polyester (UP)/nanoclay composites, the effect of electron beam (EB) irradiation on mechanical properties of UP/nanoclay composites with various nanoclay contents is investigated in this work. Moreover, influence of EB irradiation with doses of 100, 500 and 1000 kGy on tensile properties and hardness of nanocomposite was examined. FTIR spectroscopy was employed to examine the effect of irradiation on chemical structure of polymer. EB irradiation up to 500 kGy led to the improvement of tensile strength and hardness of the samples. The best mechanical properties were observed for the nanocomposite with 1 wt.% nanoclay content. As the selected nanocomposite, UP/nanoclay(1 wt.%) composite was reinforced by carbon and glass fibers and the effect of EB irradiation on the mechanical properties of the prepared UP/nanoclay/fiber composites was studied. When compared to the fiber-reinforced UP without nanoclay, presence of nanoclay particles in UP/nanoclay/fiber composites resulted in the better mechanical properties and higher radiation resistance. Hence, the UP/nanoclay/fiber composite with proper amount of nanoclay has been shown to be a dependable choice for structural applications in which the material is exposed to ionizing radiations.

Effect of Fibre Length and Sea Water Treatment on Mechanical Properties of Sugar Palm Fibre Reinforced Unsaturated Polyester Composites

This study presented the effect of different fibre length and seawater treatment on mechanical properties of the fabricated composites. The composite was reinforced with fixed 30wt.% of fibre loading. Sugar palm was treated using sea water for 30 days and have been cut into three different lengths by 5cm, 10cm and 15cm. The mechanical properties of the untreated and treated fibre with different fibre length composites were characterised includes tensile test and flexural test. Treated sugar palm fibre composites with 15cm fibre length exhibited higher tensile strength at 18.33 MPa. However, it shows the lowest value for the tensile modulus at 4251.96MPa. The flexural strength shows an increasing trend as the fibre length increased up to 15cm and the maximum flexural strength was exhibited by treated sugar palm fibre with 5 cm at 80.80MPa.Effect of Fibre Length and Sea Water Treatment on Mechanical Properties of Sugar Palm Fibre Reinforced Unsaturated Polyester Composites

Study of Dimensional Changes on Alkali Treated Zallaca Fibre Reinforced Unsaturated Polyester Composites under Different Aqueous Environments

In this research, alkali treated zallaca fibre reinforced with high density polyethylene (HDPE) composites are subjected to water immersion tests in order to study the dimensional changes and flexural properties of composites. Composites were frabricated using compression molding method with zallaca fiber content of 30% vt. Composite specimens were immersed under three different solution included distilled water, sea water and acidic solutions for 2 months at room temperature. The highest dimensional changes was recorded for composite immersed in seawater followed by acidic solution and distilled water. The dimensional changes of Zallaca fibre reinforced HDPE in different solution were found to follow a Fickian behaviour. Alkali treated fiber composites after immersion has lower results both in dimensional changes and its slope than untreated fiber composites in different aquaeous environment. The severe degradations are observed by using Scanning Electron Microscopy (SEM) that showed microcracks growth, and degradation of interfacial region between fiber and matrix. Flexural properties of composites decrease after immersion stage in different values.

Effect of adhesive thickness on the strength of steel-composite joints aged in wet environment

This paper presents the effect of adhesive layer thickness on the static strength of adhesively bonded steel-glass fiber-reinforced unsaturated polyester resin (GFRP) lap joints after being aged in water at a temperature of 60°C for 15 days. The adhesive thickness was varied from 0.1 mm to 0.5 mm. It was found that for the dry joints, the static strength increased with the increase of adhesive thickness. However, in wet condition, water really had a significant detrimental effect on the strength of the joints, as most of the strengths of wet joints were much lower than those of the dry joints. In dry condition, mode of failure changed from interfacial (at the adhesive thickness of 0.1 mm) to mix failure; however, for the wet joints; most of failures were at the interface of adhesive/steel.

The Comparative studies of mechanical and interfacial properties between jute and E-Glass fiber-reinforced unsaturated polyester resin based composites

Jute fiber (hessian cloth)-reinforced unsaturated polyester matrix composites (50 wt% fiber) were fabricated by hand lay-up technique. Tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM), elongation at break (Eb%), and impact strength (IS) of the composites were found to be 42 MPa, 2.7 GPa, 36 MPa, 2.1 GPa, 3%, and 21 kJ/m2, respectively. On the other hand, TS, TM, BS, BM, and Eb% of E-glass mat reinforced unsaturated polyester resin (UPR) composite were found to be 70 MPa, 3.8 GPa, 80 MPa, 2.5 GPa, and 5%, respectively. Then E-glass/UPR based composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the Jute/UPR based composites. It was observed that E-glass fiber-based composites showed almost double mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 21 kJ/m2 and 21.56 kJ/m2, respectively, measured using the single-fiber fragmentation test. After flexural testing, fracture sides of both types of the composites were studied by scanning electron microscope (SEM) and the results showed that poor fiber-matrix adhesion for Jute/UPR based composites when it compared to that of the E-glass fiber composites. However, it was found that the E-glass fiber based composite has better strength as compared to jute fiber composite.

Cellulose fiber-reinforced thermosetting composites: impact of cyanoethyl modification on mechanical, thermal and morphological properties

This study explores the mechanical, thermal and morphological properties of untreated and cyanoethyl-treated kempas wood sawdust cellulose fiber-reinforced unsaturated polyester composites. The fiber loadings of the composites were varied from 0 to 20 wt%, with the increment of 5 wt%. The composites were tested for water absorption, and their FTIR spectroscopy, SEM and TGA results were analyzed. The FTIR results show that the fiber treatment reduces the hydroxyl groups in the cellulose, replacing them with the cyanoethyl groups. The TGA results show that the composites are stable up to 324 °C. SEM images of the treated fiber composites showed that there were no visible gaps between fibers and matrix which indicates a strong interfacial bond. From the mechanical tests, 15 wt% fiber loading composite was strongest. Among all the composites, cyanoethyl cellulose fiber unsaturated polyester composites had the most desirable mechanical and thermal properties, whereas the fiber treatment showed the improvement of interfacial bonding.

The Effect of Alkaline Treatment on the Mechanical Properties of Treated Sugar Palm Yarn Fibre Reinforced Unsaturated Polyester Composites Reinforced with Different Fibre loadings of Sugar Palm Fibre

The aim of this paper was to describe the effects of treated sugar palm yarn fibre loading on the mechanical properties of reinforced unsaturated polyester composites. Composites with varying fibre loads (10, 20, 30, 40 and 50 wt. %) were prepared using a hand-layup process. The composites were tested for tensile, flexural and impact strength according to ASTM D3930, ASTM D790 and ASTM D256 standards, respectively. The results showed that an increase in fibre loading of up to 30 wt. % increased tensile strength (31.27 MPa), tensile modulus (4.83 GPa), flexural strength (58.14 MPa) and modulus (4.48 GPa). Maximum loading can be attained at 40 wt. % of fibre loading for impact strength (38 kJ/ m2). The effectiveness of stress transfer mechanism through the fibre-matrix interaction, coupled with the optimization of fibre loading in resisting fracture and failure, boosts the overall mechanical performance of sugar palm composite.

Preparation of Unidirectional Grewia Serrulata Fiber-Reinforced Polyester Composites and Evaluation of Tensile and Flexural Properties

ABSTRACTPartially biodegradable composites were prepared using bast fibers extracted from Grewia Serrulata trees with unsaturated polyester resin. Different durations of fiber pretreatment and volume fraction variations were tried for fabricating the composites. Hand lay-up technique was used for the fabrication; tensile strength and flexural strength of the specimens were tested following American Society for Testing and Materials (ASTM) standards. It is found that the mechanical properties of Grewia Serrulata bast fiber-reinforced unsaturated polyester composites are superior in comparison with relevant properties of unsaturated polyester resin. Such natural fiber-reinforced composites are adaptable in applications such as automotive interiors, partition walls, and false ceilings and ensures easy material disposal ways at the end of service life as raw materials used are mostly biodegradable.

Unsaturated polyester-toughened epoxy composites: Effect of sisal fiber on thermal and dynamic mechanical properties

In the present study, the mechanical and thermal properties of sisal fiber-reinforced unsaturated polyester (UP)-toughened epoxy composites were investigated. The sisal fibers were chemically treated with alkali (NaOH) and silane solutions in order to improve the interfacial interaction between fibers and matrix. The chemical composition of resins and fibers was identified by using Fourier-transform infrared spectroscopy. The UP-toughened epoxy blends were obtained by mixing UP (5, 10, and 15 wt%) into the epoxy resin. The fiber-reinforced composites were prepared by incorporating sisal fibers (10, 20, and 30 wt%) within the optimized UP-toughened epoxy blend. Scanning electron microscopy was used to analyze the morphological changes of the fibers and the adhesion between the fibers and the UP-toughened epoxy system. The results showed that the tensile and flexural strength of (alkali-silane)-treated fiber (30 wt%) -reinforced composites increased by 83% and 55%, respectively, as compared with that of UP-toughened epoxy blend. Moreover, thermogravimetric analysis revealed that the (alkali-silane)-treated fiber and its composite exhibited higher thermal stability than the untreated and alkali-treated fiber systems. An increase in storage modulus and glass transition temperature was observed for the UP-toughened epoxy matrix on reinforcement with treated fibers. The water uptake behavior of both alkali and alkali-silane-treated fiber-reinforced composites is found to be less as compared with the untreated fiber-reinforced composite. J. VINYL ADDIT. TECHNOL., 2015. © 2015 Society of Plastics Engineers