Fiber-reinforced Unsaturated Polyester Composites Research Articles

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

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

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.

Kenaf fibers reinforced unsaturated polyester composites: A review

Recently development of high-performance polymer composites made from natural resources in the various sectors is increasing tremendously due to the environmental issues and health hazard possessed by the synthetic fibers during disposal and manufacturing. Among the many different types of natural resources, kenaf fibers have been extensively investigated as an alternative reinforcement for polymer composites over the past few years due to their low cost, good mechanical properties, high specific strength, nonabrasive, eco-friendly, and biodegradability characteristics. Kenaf is regarded as an industrial crop in Malaysia and grown commercially in other parts of the world for different applications. It is certainly one of the important plants cultivated for natural fibers globally which has great potential to use as automotive and construction materials. In many research studies, kenaf fibers have been used as reinforcement in unsaturated polyester (UPE) which perfectly improved the features of the polyester resin. The tensile properties of kenaf fiber reinforced UPE are mainly influenced by the interfacial adhesion between the fibers and the polyester resin. Several chemical modifications are employed to improve the interfacial bonding between kenaf fibers and polyester, resulting in the enhancement of mechanical properties of the composites. Therefore, this paper explores and highlights of the previous studies around kenaf fiber reinforced UPE composites, in terms of processing methods, mechanical, water absorption, and morphological properties to provide a perfect source of literature for doing further research in this topic.

Effect of water and mechanical retting process on mechanical and physical properties of kenaf bast fiber reinforced unsaturated polyester composites

The properties of polymer composite filled or reinforced with kenaf fiber have been extensively studied in recent decades as an alternative for replacing synthetic fiber in composite structures. Although many studies have been conducted on natural fiber filled or reinforced composite, lack of researches have been done on the processing factors that contributed to the overall fiber strength. Thus, this study aims to determine the efficiency of retting process which significantly influences the characteristics and performance of the final composite products. In this study, the kenaf bast fibers composites were prepared using hand lay-up method at different fiber loadings (weight%) of 10, 15, 20, 25, 30 and 35 through two retting methods namely water and mechanical retting process. Unsaturated polyester (UPE) resin and methyl ethyl ketone peroxide (MEKP) were used as binder and catalyst, respectively. This current research aims to examine the effects of different retting processes and fiber loadings on tensile strength, water absorption and morphology which consists of tensile fracture and fiber surface, using Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The tensile strength of water retted kenaf bast fibers reinforced UPE composites exhibited higher value than mechanical retted kenaf bast fibers reinforced UPE composites. In terms of water absorption, it was found that mechanical retted kenaf bast fiber reinforced UPE composites absorb more moisture than water retted kenaf bast fibers reinforced UPE composites. From the results, it can be concluded that the water retting process yielded higher mechanical and water absorption properties compared to mechanical retting process at all different fiber loadings (weight%). This current study contributes to the current field of knowledge by providing a clear reference for future development of high-performance polymer composites based on kenaf bast fibers as reinforcements, specifically in structural applications such as floor decking, door and window frames.

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.

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.

Improvement of Interfacial Adhesion in Natural Plant Fiber-reinforced Unsaturated Polyester Composites: A Critical Review

Natural plant fiber-reinforced unsaturated polyester (UPE) composites have lower strengths and absorb more water than glass fiber-UPE composites because of the incompatibility between hydrophilic natural fibers and hydrophobic UPE. The good interfacial adhesion between the natural fibers and the UPE matrix is essential for the superior mechanical properties and good water resistance for the natural fiber-UPE composites. Extensive work has been done on the improvement of the interfacial adhesion. This paper reviews various physical and chemical methods used in the treatments of natural fibers for the improvement of the interfacial adhesion. Physical methods include plasma and heat treatments of natural fibers. Chemical methods include alkaline treatments, acetylation, and benzoylation of natural fibers, the use of coupling agents, and in-situ polymerizations of acrylic acid, acrylonitrile, and styrene in the presence of natural fibers. Mechanisms by which these physical and chemical methods improve the interfacial adhesion between the natural fibers and the UPE matrix are discussed in detail. The effects of these methods on the improvements of mechanical properties and water resistance of the resulting natural fiber-UPE composites under the best conditions reported are also reviewed.

Investigation of bamboo pulp fiber-reinforced unsaturated polyester composites

AbstractMechanical pulp fibers (MPFs) and chemical pulp fibers (CPFs) from moso bamboo have been characterized in terms of their length and width distributions, and their reinforcing effects in unsaturated polyester (UPE) composites have also been investigated. CPF-UPE composites had much higher tensile strength, flexural strength, and flexural modulus than MPF-UPE composites. CPF-UPE composites also absorbed less water than MPF-UPE composites. Treatments of the fibers with a combination of 1,6-diisocyanatohexane (DIH) and 2-hydroxyethyl acrylate (HEA) significantly increased the tensile strength, flexural strength, flexural modulus, and water resistance of the resulting composites. Fourier transform infrared and X-ray photoelectron spectroscopy analyses indicated that DIH-HEA was bound onto bamboo fibers (BFs) via carbamate linkages. The scanning electron microscopy images of the tensile-fractured surfaces of the composites revealed that the DIH-HEA treatments for BFs greatly improved the interfacial adhesion between the fibers and UPE resins.

Tensile Properties of Pineapple Leaf Fibre Reinforced Unsaturated Polyester Composites

In recent years natural fibres such as sisal, jute, kenaf, pineapple leaf and banana fibres appear to be the outstanding materials which come as the viable and abundant substitute for the expensive and non-renewable synthethic fibre. This paper investigate the effect of fibre length and fibre content on the tensile properties of pineapple leaf fibre (PALF) reinforced unsaturated polyester (UP) composites. PALF as reinforcement agent will be employed with UP to form composite material specimens. The various of fiber length (<0.5, 0.5–1, and 1-2 mm) and fibre content (0, 5, 10 and 15 % by volume) in UP composite have been studied. The fabrication of PALF/UP composites used hand lay-up process, and the specimens for tensile test prepared follow the ASTM D3039. The result obtained from this study show that the 1-2 mm fibre length has higher tensile strength (42 MPa) and tensile modulus (1344 MPa) values compared to fibre length of <0.5 mm (30 MPa and 981 MPa) and 0.5-1 mm (35.40 MPa and 1020 MPa) respectively. Meanwhile, for the effect of various fibre content in study has shown that the increase of fibre content has decreased in tensile strength dan tensile modulus of composites. The increase of fibre content due to poor interfacial bonding and poor wetting of the fibre by unsaturated polyster. The treatment of natural fibre are suggested in order to improve the interfacial adhesion between natural fibre and the unsaturated polyester.

The effect of argon and air plasma treatment of flax fiber on mechanical properties of reinforced polyester composite

Flax fibers were modified by argon and air atmospheric pressure plasma treatments to improve the mechanical properties of flax fiber-reinforced unsaturated polyester composites. Plasma treatments were carried out at plasma powers of 100, 200, and 300 W. Both plasma surface treatments were conducted to improve the tensile strength, tensile modulus, flexural strength, flexural modulus, interlaminar shear strength (ILSS), Mode I interlaminar fracture toughness (GIC), and Mode II interlaminar fracture toughness (GIIC). Moreover, the maximum improvement in the mechanical properties was obtained after air plasma treatment of flax fiber at a plasma power of 300 W. Tensile strength, flexural strength, ILSS, GIC, and GIIC values of flax fiber-reinforced polyester composites increased by nearly 34%, 31%, 39%, 35%, and 42%, respectively. However, for argon plasma-treated flax fiber-reinforced polyester composites, the mechanical properties of composite increased up to argon plasma power of 200 W.

Effects of Alkali Treatment and Polyisocyanate Crosslinking on the Mechanical Properties of Kraft Fiber-Reinforced Unsaturated Polyester Composites

The effects of alkali treatment and polyisocyanate crosslinking on the mechanical properties of kraft fiber-reinforced UPE composites were investigated by means of tensile evaluation, SEM analysis, and XRD analysis. The results indicated that the alkali treatment decreased the tensile strength of the prepared composite before aging from 121 MPa to 97 MPa due to the decreased degree of crystallinity of the alkali-treated kraft fiber. Polyisocyanate crosslinking could apparently improve the mechanical properties and stability in terms of a 43% increase of non-aged tensile strength and 52% increase of hydrothermal-aged tensile strength compared with the controlled composite without crosslinking modification, which was attributable to the formation of strong chemical bonding between the interfaces of kraft fiber and polyester.

Tensile Properties of Kenaf Yarn Fibre Reinforced Unsaturated Polyester Composites at Different Fibre Orientations

This paper reported the study of tensile properties of kenaf yarn fibre reinforced unsaturated polyester (UP) composites at different fibre orientations, i.e. 0o, ±45o and 90o. It is concluded that composites with 0o orientation show higher strength and stiffness than composites with ±45o and 90o angle fibre orientation. The highest value of stress is 29 MPa for 0o loading direction followed by ±45o loading direction (28 MPa) and 90o loading direction has the lowest stress value of 6 MPa. Tensile modulus results revealed the highest value of 10.61 GPa for 0o loading direction and the tensile modulus for 45o orientation of loading direction is 5 GPa, followed by the modulus for 90o of fibre loading direction of 1.2 GPa; which is the lowest.

Tensile Strength of Untreated Napier Grass Fibre Reinforced Unsaturated Polyester Composites

This paper describes the experimental investigation of the tensile strength of untreated Napier grass fibre reinforced polyester composites. Napier grass fibres were extracted trough conventional water retting process and used as reinforcing materials in the polyester composite laminates. Tensile tests were then conducted for the composite specimens from the laminates at 25% fibre loading using the electronic extensometer setup to obtain the tensile properties. The results show significant differences in tensile strength between random short fibres laminates and random long fibre laminates with the long fibres yield almost 45 % higher in the strength. The laminates also show higher maximum strength compared to other commonly available natural fibre composites with over 70 % increase in the maximum strength compared to the short kenaf fibre reinforced composites.