Papers by Keyword: Unsaturated Polyester

Abstract: The aim of this work is the studyof the degradation mechanism of a glass fiber/unsaturated polyester (UP) composite immersed inacidic(H₂SO₄)and alkaline(NaOH)solutionslike establishing a relation between the chemical and the mechanical behaviors of this material. The gravimetric analyses showed a pseudo fickianbehavior for the samples immersed in H₂SO₄ and mass losses with a pseudo-stage of saturation as from 64 hours of immersion for the samples immersed in NaOH.The Fourier transform infrared analysis (FT-IR)of the UP resin revealed the presence of chemical degradation phenomenon (hydrolysis).Microscopic observations (SEM) confirmed the fibres/matrix interfacesdegradation. The effect of these degradations has been reflected one the mechanical properties of the materials.

Abstract: This study investigated the effect of heatingtime during heat treatment on mechanical and physical properties of the kenaf fiber and its composites. Kenafbast fibers were modified by heat treatmentat 140°C for2.5, 5, 7.5, 10 and 12.5 hours. Composites were fabricated by resin transfer molding process with unsaturated polyester as matrices and needle-punched kenaf fiber mat as reinforces. The fiberswerecharacterized by Fourier Transform-Infra Red (FT-IR) and X-Ray Diffraction (XRD). FT-IR resultsshowedthe changesin intensity ofhemicelluloce wavelength (1736 cm^-1). Besides XRD observation also confirmed the increase of cellulose content in kenafthat described to the increase of crystallinity index ofkenaf fiber with heat treatment. The single fiber strength investigation stated that the highest strength and modulus was obtained bykenaf fiber heated for10hours indrying oven. SEM observation showed the decreasing numbers of impuritieson thefibers surface with fiber treatment compared to untreated kenaf fibers. The flexural properties of composites showed a similar trend to fiber strength, but the fracture toughnesshas showedcontrary results.

Abstract: 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.

Abstract: Non-woven kenaf fiber mats were prepared from untreated and alkali treated fibers by using a carding machine followed by needle punching. The alkali treatment was carried out by immersing the fiber mats in 6% NaOH solution for 0, 1, 2, 3, 4, and 5 h at room temperature. The untreated and alkali treated fiber mats were impregnated with unsaturated polyester resin via a resin transfer molding technique to form composites. Maximum improvements of flexural strength and flexural modulus of the composites were observed when the fiber mat was alkali treated for 3 h. The improved of both properties can be attributed to better fiber-matrix adhesion between the alkali treated kenaf fiber and the unsaturated polyester matrix most probably via mechanical interlocking. Water absorption tests were conducted by immersing the composite samples in distilled water at room temperature. The water absorption patterns of all the composites were found to follow Fickian behavior. The tendency of the composites to absorb water decreased when the alkali treated fiber mats were used.

Abstract: In this paper, meso-porous MCM-41 was synthesized at room temperature using cationic surfactant cetyltrimethylammonium bromide (CTAB) as the template agent. Then MCM-41/unsatura-ted polyester resin (UPR) materials were prepared by in-situ polymerization with the meso-porous MCM-41. MCM-41/UPR in-situ composites were prepared by roller milling and molding processes. Effects of meso-porous MCM-41 on rheological properties and wear resistance of the MCM-41/UPR composites have been investigated. It is shown that MCM-41 has a diameter in range of 4-5 nm and the pores are highly ordered. MCM-41 can improve the rheological properties and wear resistance of the composites. When MCM-41 content is 2%, the mass abrasion loss is decreased by 37.4%.

Abstract: O-MMT treated unsaturated polyester based hybrid composites were prepared using keratin fiber obtained from chicken feathers. Fibers of similar dimension were selected to fabricate composites through hand lay-up method. The preparation and dimensional stability properties of keratin fiber as reinforcements in composites is outlined in this paper. Varying O-MMT contents in nancomposites is performed to investigate the effects on the dimensional stability (water absorption and thickness swelling) of the composites. Results indicated that increasing fiber content deteriorates dimensional stability of the composites and composites. However, improvements in dimensional stability of the keratin fibercomposites were observed with O-MMT. O-MMT treatment reduces the water absorption and thickness swelling, especially at 5wt% of O-MMT concentrationat all range of fiber content. At 5wt% concentration of O-MMt, 10wt% keratin fiber content marks the lowest water absorption and thickness swelling with rate of 0.65% and 1.93%, respectively. Adopting 10wt% of keratin fiber at 5wt% of O-MMT can be utilized for application requiring high dimensional stability.

Abstract: 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 0^o loading direction followed by ±45^o loading direction (28 MPa) and 90^o loading direction has the lowest stress value of 6 MPa. Tensile modulus results revealed the highest value of 10.61 GPa for 0^o loading direction and the tensile modulus for 45^o orientation of loading direction is 5 GPa, followed by the modulus for 90^o of fibre loading direction of 1.2 GPa; which is the lowest.

Abstract: This study uses in-situ polymerization method due to organic modified montmorillonite into unsaturated polyester to form a advanced montmorillonite / unsaturated polyester (MMT /UP) nanocomposites. Using of the blasting force generated in situ polymerization patterns show the formation of clay layers is exfoliation structure in polymer and improving of thermal properties, flame retardant properties, and mechanical properties.The d-spacing of organic modified clay could be determined whether the modifier was intercalated into the gallery of clay by applying the wide-angle X-ray diffraction (WXRD). The functional groups of modified clay were measured by Fourier infrared spectroscopy (FT-IR). The dispersion morphologies of MMT / UP nanocomposites were characterized by the wide-angle X-ray diffraction (WXRD) and transmission electron microscopy (TEM). The thermal properties and mechanical properties were investigated by thermal gravimetric analysis (TGA), limiting oxygen index meter (LOI), cone calorimeter (Heat Release Rate) and a dynamic mechanical analyzer (DMA).

Abstract: In this research, the impact properties of unsaturated polyester (UPR) composites filled with empty fruit bunch palm oil (EFBPO) and cellulose were investigated. The composites were made by hand-lay up method by mixing UPR with the content of each fillers (EFBPO and cellulose) of 5,10,15,20 wt.%. The parameter which was carried out on the prepared samples was impact test. It was found that the addition of fillers to the matrix caused the impact strength of composites increased at 10% addition of EFBPO and 5% addition of cellulose. The results were confirmed by fourier transform infra-red (FTIR) and supported by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM).

Abstract: The biocomposites were prepared by using kenaf bast fiber mat as reinforcing materials at different percentage. The kenaf bast fiber was treated with alkaline at different sodium hydroxide (NaOH) percentage. Composites which were made from treated alkaline kenaf treated bast fiber showed better mechanical properties (tensile) than those of the unmodified. Scanning electron microscope analysis showed the evidence of the enhancement of the compatibility between kenaf bast fiber and the matrix. The percentage of kenaf fiber in composites also plays a crucial role in determining the composite properties.