Fibre-reinforced polymer composites mechanical properties

Selzer R, Friedrich K, Mechanical properties and failure behaviour of carbon fibre reinforced polymer composites under the influence of moisture. Composites Part A—Appl Sci Manuf 28(6), 595-604, 1997. 

Siregar JP, Sapuan SM (2009) Mechanical properties of pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composites. In Sapuan SM (ed) Research in natural fibre reinforced polymer composites. UPM, Serdang, Selangor, Malaysia... 

Herrera PJ, Gonzalez AV (2004) Mechanical properties of continuous natural fibre-reinforced polymer composites. Compos A 35 339-345... 

Therefore, the first and the most important problem is the fibre-matrix adhesion. The role of the matrix in a fibre-reinforced composite is to transfer the load to the stiff fibres through shear stresses at the interface. This process requires a good bond between the polymeric matrix and the fibres. Poor adhesion at the interface means that the full capabilities of the composite cannot be exploited and leaves it vulnerable to environmental attacks that may weaken it, thus reducing its life span. Insufficient adhesion between hydrophobic polymers and hydrophilic fibres result in poor mechanical properties of the natural fibre-reinforced polymer composites. Pre-treatments of the natural fibre can clean the fibre surface. 

Natural fibre-reinforced polymer composites are considered as replacement for metals or carbons in situations where they have better mechanical properties. But the thermal properties of these composites are in general much lower than that of metals. Consequently, it is more difficult to dissipate the heat, and in some situations this can be an important consideration, particularly if electronic components... 

Key words fibre-reinforced polymer composites, polyester, theimoset polymers, composites, reinforced polymers, construction materials, mechanical properties. 

Singha AS, Thakur VK (2008a) Mechanical properties of natural fibre reinforced polymer composites. Bull Mater Sci 31 791-799... 

The performance of natural fibre reinforced polymer composites depends on several factors, including fibre chemical composition, cell dimensions, microfibrillar angle, defects, structure, physical and mechanical properties, and the interaction of a fibre with the polymeric matrix [28]. The knowledge about the characteristics of the fibre is essential in order to expand the effective use of lignocellulosic materials for polyethylene composites and to improve their performance. 

With environmental awareness, natural fibre reinforced polymer composites have been expanding their application in sectors such as the automotive, construction, and packaging industries as a replacement for inorganic fibre reinforced polymer composites. Currently, glass fibre is one of the most widely used fibres to reinforce polymers, which can give superior mechanical properties. 

Akihama S, Suenaga T, Nakagawa T, Suzuki K, Influence of fibre strength and polymer impregnation on the mechanical properties of carbon fibre reinforced cement composites. Development in Fibre Reinforced Cement and Concrete, Proc RILEM Symposium 1988, Sheffield, Paper 2.3, 1988. 

Bacterial cellulose-modified sisal and hemp fibres have also been used to produce unidirectional natural fibre reinforced CAB and polylactide (PLLA) model composites [9]. The mechanical properties of bacterial cellulose-coated sisal fibre reinforced polymers showed significant improvements over neat polymers (Table 6.8). The tensile strength and modulus for sisal/PLLA composites improved by as much as 68 and 49%, respectively. However, improvements were... 

Chen X, Qipeng G, Yongli M (1998) Bamboo fiber-reinforced polypropylene composites a study of the mechanical properties. J Appl Polym Sci 69 1891-1899 Chow CPL, Xing XS, Li RKY (2007) Moisture absorption studies of sisal fibre reinforced polypropylene composites. Compos Sci Technol 67 306-313... 

Pineapple leaf fibre (PALF), which is rich in cellulose, relatively inexpensive and abundantly available has the potential for polymer-reinforced composite. PALF at present is a waste product of pineapple cultivation. Hence, without any additional cost input, pineapple fibres can be obtained for industrial purposes. Among various natural fibres, PALFs exhibit excellent mechanical properties. These fibres are multicellular and lignocellulosic. They are extracted from the leaves of the plant Ananus cosomus belonging to the Bromeliaceae family by retting. The main chemical constituents of pineapple fibres are cellulose (70-82%), lignin (5-12%) and ash (1.1%). The superior mechanical properties of PALFs are associated with their high cellulose content. 

George et al. [27] studied stress relaxation behaviour of pineapple fibre-reinforced polyethylene composites. They found stress relaxation to be decreased with an increase of fibre content due to better reinforcing effect It is also reported by George et al. [28] that properties of fibre-reinforced composites depend on many factors like fibre-matrix adhesion, volume fraction of fibre, fibre aspect ratio, fibre orientation as well as stress transfer efficiency of the interface. Luo and Netravah [29] found an increase in the mechanical properties of green composites prepared from PALFs and poly(hydroxybutyrate-co-valerate) resin (a biodegradable polymer) with the fibres in the longitudinal direction. However, the researchers reported a negative effect of the fibres on the properties in the transverse direction. 

H. Ismail, N. Rosnah, and H.D. Rozman, Effects of various bonding systems on mechanical properties of oil palm fibre reinforced rubber composites. Eur. Polym. J. 33, 1231-1238 (1997). 

Licea-Claverie and co-workers [57] studied mechanical stress-strain, impact properties and also thermal properties of PA 6,6 (including some recycled PA) with mixed glass fibre and carbon fibre reinforcements and compared these properties with those of the virgin polymers. No dependence on mechanical properties because of increasing amounts of scrap in the composites was found up to 10.4 wt%. The recycled composites generally showed lower mechanical properties when compared with the virgin composites because of a poor matrix-fibre adhesion. 

Fibre-reinforced polymer (FRP) composites are composed of fibres and matrices, which are bonded through the interface to ensure that the composite system as a whole gives satisfactory performance. Part 1 deals with FRP composite matrix materials which provide the foundation for composite materials. Chapter 2 reviews the chemistry of phenolic resins together with their mechanical and thermal properties. Chapter 3 discusses polyester thermoset resins as matrix materials. An overview of the chemistry of vinylester resins, together with their mechanical and chemical properties, as well as their use as a matrix material in the construction industry, is provided in Chapter 4. The final chapter in Part 1 begins with a review of the epoxy resins commonly available on the market, and then focuses on the principal characteristics of epoxy resin composite systems and their practical applications. 

The mechanical properties of FRP composites are dependent upon the ratio of fibre and matrix material, the mechanical properties of the constituent materials, the fibre orientation in the matrix, and ultimately the processing and methods of fabrication, which are the subject of Part II. Chapters discuss prepreg processing, liquid composite moulding (LCM), filament winding processes and pultrusion of advanced fibre-reinforced polymer (FRP) composites. 

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