CARBON-FIBER POLYMER RESIN COMPOSITES

G. Lu, X. Li, H. Jiang, and X. Mao, Electrical conductivity of carbon fibers/ABS resin composites mixed with carbon blacks,. Appl. Polym. Sci., 62(13) 2193-2199, December 1996. 

Choi, M.H., Jeon, B.H., and Chung, l.J. (2000) The effect of coupling agent on electrical and mechanical properties of carbon fiber/phenolic resin composites. Polymer 41, 3243-3252. 

The state of stress can dramatically affect the failxire mode and strength of polymers. This effect alters the fracture surface characteristics when different modes of fracture are applied. Figure 31 shows comparative micrographs of fracture surfaces in carbon fiber epoxy resin composites tested in mode I (opening mode) and mode II (sheeir mode) loading conditions. Notice that the mode I fracture surface appears relatively smooth while the mode II surface has a characteristic hackled surface. Also, the fracture energy for the mode n sample is greater than that of the mode I sample. 

Wright, W.W. (1990). The carbon fiber-epoxy resin interfaces-a review, part I. In Composite Polymer Vol, 3. (P. Dickin, ed.), pp. 231-401. 

The use of epoxidized hyperbranched polyesters as toughening additives in carbon-fiber reinforced epoxy composites has been demonstrated (Boogh et al., 1995). Since a hyperbranched resin has a substantially lower viscosity and much shorter drying time than a conventional (less branched) resin of comparable molecular weight, hyperbranched polymers have been used as the base for various coating resins (Pettersen and Sorensen, 1994). 

Low energy radiation can penetrate reasonable thicknesses of a polymer matrix composite and 1 MeV X-rays are able to penetrate 500 mm of polymer. The efrp have low X-ray absorption and consequently, low voltage, low energy X-rays have to be used in conjunction with high contrast recording techniques, which can then detect transverse cracks and inclusions. Unfortunately, carbon fibers and resin matrices have similar mass absorption coefficients and cannot be differentiated. Glass, on the other hand, can be readily detected and can be used in composite construction as a radio-opaque tracer, showing the direction of fiber lay-up. 

Lignin is part of the composition of natural polymers in variable proportions. The aromatic structure of the lignin can be used as source of several phenolic products, which may substitute petroleum-based compounds. Bio-based composites have gained prominence over the past two decades owing to both environmental concerns and waste disposal problems. Lignin-based biomaterials include carbon fibers, polymer modifiers, resin/adhesives/binders and others. 

Carbon—Carbon Composites. Above 300°C, even such polymers as phenoHcs and polyimides are not stable as binders for carbon-fiber composites. Carbon—carbon composites are used at elevated temperatures and are prepared by impregnating the fibers with pitch or synthetic resin, foUowed by carbonization, further impregnation, and pyrolysis (91). 

Cai H, Bashar MT, Picot JJC (2004). Thermal and mechanical anisotropy in compression molded carbon fiber/resin composites. Polymer Composites 26 684-688. 

Most carbon fibers use PAN as their precursor however, other polymer precursors, such as rayon [8], pitch (a by-product of petroleum or coal-coking industries), phenolic resins, and polyacetylenes [6,7], are available. Each company usually uses different precursor compositions for its products and thus it is difficult to know the exact composition used in most commercially available carbon fiber products. 

Engineering thermoplastics have also been used in preimpregnated constructions. The thermoplastic is thoroughly dispersed as a continuous phase in glass, other resins, carbon fibers (qv), or other reinforcement. Articles can be produced from these constructions using thermoforming techniques. For example, the aerospace industry uses polyetheretherketone (PEEK) in woven carbon-fiber tapes (26). Experimental uses of other composite constructions have been reported (27) (see also COMPOSITE MATERIALS, POLYMER-MATRIX). 

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