Carbon fibers carbonization methods

It is assumed that k and trp depend on the filling ratio (Vf), fiber modulus, method of fabrication. In [151] for example, the k for carbon fiber bundles has been found to be ... 

These differences in the chemical structure of the surface depend not only on the process of manufacture but also on additional treatments or processing conditions. In oxidized carbon fibers, the concentration of carbonyl and, more particularly carboxyl groups, is substantially increased at the expense of hydroxyl groups. In the treatment of carbon fibers, several methods of oxidation are used. Liquid phase oxidation is carried out by the electrochemical and chemical methods whereas gaseous oxidation is carried out in air, oxygen or in the presence of catalysts. Plasma treatment is also used for the surface oxidation of formed fibers. Different methods of oxidation produce different surface characteristics. For example, interlaminar strength is improved by a factor of 10 by electrolytic oxidation over crude oxidation in air. 

Mitsubishi Rayon, Co.,L. Q.QQ ). Acrylonitrile-based precursor for carbon fiber and method for production thereof. 

Martin-Gullon, L, R. Andrews, M. Jagtoyen, and F. Derbyshire. 2001. PAN-based activated carbon fiber composites for sulfur dioxide conversion Influence of fiber activation method. Fuel 80(7) 969-977. 

Ramesh, N.S., Lee, S.T. Blowing agent effect on extensional viscosity calculated from fiber spinning method for foam processing , SPE Foams 99 (1999), 85-96 Werner, R, Verdejo, R., Wdllecke, F., Altstadt, V., Sandler, J.K.W., Shaffer, M.S.P. Carbon nanofibres allow foaming of semicrystalline poly(ether ether ketone) , Adv. Mater. 17(23) (2005), 2864-2869... 

Fig. XVII-31. (a) Nitrogen adsorption isotherms expressed as /-plots for various samples of a-FeOOH dispersed on carbon fibers, (h) Micropore size distributions as obtained by the MP method. [Reprinted with permission from K. Kaneko, Langmuir, 3, 357 (1987) (Ref. 231.) Copyright 1987, American Chemical Society.]...

Silicon-containing Pis, useflil as insulation and protective materials, demonstrate adhesion to fibers, fabrics, glass, quartz, and carbon (36). The synthetic method used is the reaction of the silicon-containing dianhydride with diamines. 

In the calendering method, a PVC compound which contains plasticizers (qv) (60—120 phr), pigments (qv) (0—10 phr), fillers (qv) (20—60 phr), stabilizers (10—30 phr), and other additives, is kneaded with calender roUs at 150—200°C, followed by extmsion between clearance-adjusted roUs for bonding onto the substrate. This method is employed for products with thick PVC layers, ie, of 0.05—0.75 mm thickness. The main plasticizer used is di-2-ethylhexyl phthalate (DOP). For filler to reduce cost, calcium carbonate is mainly used. A woven or knit fabric made of cotton, rayon, nylon, polyester, and their blend fiber is used as substrate. For foamed vinyl-coated fabrics, the bonded materials are heated in an oven to decompose the foam-blowing... 

BenZotrichloride Method. The central carbon atom of the dye is supphed by the trichloromethyl group from iJ-chlorobenzotrichloride. Both symmetrical and unsymmetrical triphenyhnethane dyes suitable for acryhc fibers are prepared by this method. 4-Chlorobenzotrichloride is condensed with excess chlorobenzene in the presence of a Lewis acid such as aluminium chloride to produce the intermediate aluminium chloride complex of 4,4, 4"-trichlorotriphenylmethyl chloride (18). Stepwise nucleophihc substitution of the chlorine atoms of this intermediate is achieved by successive reactions with different arylamines to give both symmetrical (51) and unsymmetrical dyes (52), eg, N-(2-chlorophenyl)-4-[(4-chlorophenyl) [4-[(3-methylphenyl)imino]-2,5-cyclohexadien-l-yhdene]methyl]benzenaminemonohydrochloride [85356-86-1J (19) from. w-toluidine and o-chloroaniline. 

Carbon Composites. In this class of materials, carbon or graphite fibers are embedded in a carbon or graphite matrix. The matrix can be formed by two methods chemical vapor deposition (CVD) and coking. In the case of chemical vapor deposition (see Film deposition techniques) a hydrocarbon gas is introduced into a reaction chamber in which carbon formed from the decomposition of the gas condenses on the surface of carbon fibers. An alternative method is to mold a carbon fiber—resin mixture into shape and coke the resin precursor at high temperatures and then foUow with CVD. In both methods the process has to be repeated until a desired density is obtained. 

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