Back SearchTitle: MECHANICAL PROPERTIES OF NANOCOMPOSITES FROM BALL MILLING GRAFTED NANO-SILICA/POLYPROPYLENE BLOCK COPOLYMER
Page Range: p.257-267
Author(s): Wen Hong Ruan; Ming Qui Zhang, Min Zhi Rong, Friedrich K
File size: 230K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
This work demonstrates that the tensile performance of ethylene-propylene block copolymers can be improved by a low loading of nano-silica, pre-treated by ball milling-initiated graft polymerisation and incorporated into the matrix polymer using a conventional compounding technique. The work confirmed that the copolymer chains were chemically bonded to the silica particles during the mechanochemical grafting in the ball mill. The enhanced interfacial interaction of the grafted nanoparticles exhibited a nucleating effect and improved the crystallinity of the polymer matrix, it was shown. In addition, these particles also were shown to have a toughening effect on the amorphous polypropylene phase due to entanglements between the grafting polymer and the matrix. As a result, the tensile strength and modulus of the nanocomposites could be significantly increased by the use of low loadings of the treated nanoparticles, and this technical route is proposed for the fabrication of polymer composites with inorganic nanoparticles. 33 refs.
Title: A FRESNEL'S REFLECTION OPTICAL FIBER SENSOR FOR THERMOSET POLYMER CURE MONITORING
Page Range: p.269-276
Author(s): Vacher S; Molimard J; Gagnaire H; Vautrin A
File size: 132K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
In order to monitor the degree of cure of a fibre reinforced epoxy resin during the manufacturing process, an optical method is proposed. The proposed sensor is based on the Fresnel's reflection at the cleaved end of the optical fibre. It can be used to follow the cure of epoxy resin systems, and can serve as an on-line monitoring system for changes in the resin's optical properties during the cure process. The cure state of the polymer composite was determined in-situ during the fabrication process by monitoring the intensity of the reflected light. A calibration method for the measurement system based on the decrease in the refractive index during the heating of the resin is also presented. By using an in-situ monitoring system, real-time adjustments could be made to optimise the cure cycle. It is claimed that the technique not only reduces the manufacturing cost by reducing the time needed to determine the correct manufacturing parameters, but also to improve the reliability and service life of composite structures made therefrom. 21 refs.
Title: DURABILITY OF GLASS-FIBRE REINFORCED POLYMER COMPOSITES IN AQUEOUS AND HIGH TEMPERATURE ENVIRONMENTS
Page Range: p.277-288
Author(s): Ellyin F
File size: 207K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
An investigation was carried out into the durability of glass fibre-reinforced epoxy composites. The objectives were to investigate the absorption behaviour of specimens immersed in distilled water at different temperatures; to investigate the degradation of mechanical properties of specimens due to immersion, dry-out and effect of temperature; and to determine the applied strain at which a transverse crack initiates in the exposed laminates, and the rate of crack accumulation versus the applied strain. A strong synergy was found between temperature and environment. Immersion in distilled water at ambient temperatures did not affect the mechanical properties, but rather increased the threshold strain to crack initiation. Exposure to cycles of wet and dry conditions at high temperatures caused the most damage. 14 refs.
Title: THE PREPARATION OF SELF-REINFORCED SISAL FIBER COMPOSITES
Page Range: p.297-307
Author(s): Xun Lu; Ming Qui Zhang, Min Zhi Rong; Da Lei Yue; Gui Cheng Yang
File size: 793K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
Self-reinforced sisal composites were prepared by cleaning sisal fibres, treating them with a sodium hydroxide solution and benzylating them with benzyl chloride. This treatment converted the skin layers of the fibres into thermoplastic material, leaving the core of the fibre cells unchanged. Using the hot pressing technique, self-reinforced , all-plant fibre composites of sisal could be prepared in which plasticised sisal serves as the matrix, and the unplasticised cores of the fibres as reinforcement. This work examines the effect of the reaction conditions such as alkalinity, temperature and the extent of benzylation, and structural characteristics, melt flow and mechanical properties of the modified sisal and their composite sheets, were analysed. It was found that a balance between melt processability and the reinforcing effect of the benzylated sisal fibres was required. 15 refs.
Title: COMPRESSION FAILURE MECHANISMS OF 3-D ANGLE INTERLOCK WOVEN COMPOSITES SUBJECTED TO LOW-ENERGY IMPACT
Page Range: p.309-320
Author(s): Chiu C H; Lai M H; Wu C M
File size: 591K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
The objective of this study was to investigate the residual compressive strength and micro-failure mechanism of 3-D interlock woven/epoxy composites. An instrumented drop weight impact testing system was used to induce damage in the 3-D composites, and ultrasonic C-scan and optical microscopy were used to identify the damage areas and micro-failure mechanisms after low energy impact. For comparison, conventional two-dimensional plain woven/epoxy laminated composites were also prepared for assessment. Results showed that delamination was restricted by the interlace construction and the larger crimp angle of the 3-D interlock composites. 18 refs.
Title: FABRICATION AND MECHANICAL PROPERTIES OF PE/PE INTERFACE-LESS COMPOSITES USING MICRO-BRAIDING
Page Range: p.321-332
Author(s): Higuchi Yuji; Nakai Asami; Hiroyuki H
File size: 918K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
The influence of impregnation conditions on the tensile performance of braided PE/PE interface-less composites is studied by tensile testing and by observation of the cross-sections. Unidirectional fibre reinforced thermoplastic composites were made by micro-braiding using ultra high molecular weight polyethylene fibres as the reinforcing fibre, and low density polyethylene fibre as the matrix resin fibre to create PE/PE interface-less composite materials using various temperatures and compression times. It was found that to disperse the reinforcement fibre bundles in micro-braided yarn (middle-end fibre) was a more effective way to improve tensile strength than concentrating the reinforcement fibre bundles in the centre of the micro-braided yarn (axial fibre), because the permeation of the matrix resin into the reinforcement fibre of the middle-end fibre is easier than that of the axial fibre. The tensile strength was shown to reflect the degree of impregnation, whereas tensile modulus reflected the structure of the micro-braided yarn, i.e. the distance of impregnation. 12 refs.
Title: SURFACE SMOOTHNESS OF GLASS MAT REINFORCED POLYPROPYLENE STAMPABLE SHEET
Page Range: p.333-339
Author(s): Yamaguchi S; Tanigaki E; Hamada H
File size: 113K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
In order to improve the surface smoothness of stampable sheets made of long glass fibre reinforced PP for exterior automotive applications, a study was made of the moulding conditions needed for good surface smoothness. Results indicated that surface smoothness is affected by mould temperature. When the mould temperature was near the melting temperature of the resin, the products had high surface smoothness, but this condition was not appropriate for mass production since it lengthened the production cycle. 6 refs.
Title: A LITERATURE REVIEW OF PINEAPPLE FIBRE REINFORCED POLYMER COMPOSITES
Page Range: p.341-348
Author(s): Arib R M N; Sapuan S M; Hamdan M A M M; Paridah M T; Zaman H M D K
File size: 156K
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Issue Year: ppc
Volume: 12
Issue No: No. 4
Abstract
A literature review is presented on the development, mechanical properties and uses of pineapple leaf fibre reinforced polymer composites. The mechanical properties of such composites are discussed with reference to previous research findings, and chemical, thermal and physical properties are also examined. Research discussed includes the use of both thermosetting and thermoplastic resins as matrices for pineapple leaf fibre composites, with use of short fibres predominating as reinforcement. Manufacturing techniques covered include injection moulding, hand lay-up and compression moulding for the manufacture of composite samples. 21 refs.