Sizing Carbon Fiber

The application of a coating is normally termed a size or finish and can be achieved by  

Deposition of a polymer onto the fiber surface by electrodeposition 

Sizing is reputed to improve inter-filamentary adhesion, aid in wetting out the fiber in resin matrices and act as a lubricant to prevent fiber damage during subsequent textile processing such as weaving. 

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Fig. 2.13. Spectra of unsized and sized carbon fibers obtained from AES. After Cazeneuve et al. (1990).

It is often necessary to compare the adsorption of DOM by different activated carbons one approach is to plot surface area or pore volume normalized Isoflrerms. To do so, it is necessary to identify the pore regions accessible to DOM, which is challenging as a result of the size distribution of both carbon pores and DOM components. The results obtained with uniform pore size carbon fibers Indicate that carbon pores smaller than 1 nm are most likely not accessible for DOM molecules. Therefore, as a result of their different sizes, different DOM components will adsorb in different regions of carbon pores larger than 1 nm. 

Another commonly used surface modification method of the reinforcing fibers consists in the treatment with aminoalkylsilanes, for example y-aminopropyltriethoxysilane. Glass fibers, which have been sized in this manner, are incorporated in numerous PPE-containing compositions. In addition, it is always necessary to modify the composition of the thermoplastic matrix to bond the fibers to the matrix. In addition to glass fibers, carbon fibers, e.g., epoxy resin-sized carbon fibers have been used for reinforcement. ... 

In order to form dopamine sensing devices, N-vinylcarbazole polymers were electrochemically coated onto xm sized carbon fibers [216]. As solutions, lithium perchlorate/acetonitrile, sodium perchlorate/acetonitrile, and tetraethylammonium tetratluoroborate/acetonitrile were used. In this way, dopamine sensing layers on the carbon fiber micro-electrodes were formed. 

Table 9.7 Shell waterborne resins suitable for sizing carbon fiber...

Figure 12.48 Positive ToF-SIMS spectra for RK30 epoxy sized carbon fiber. Source Work undertaken by...

Alexander and Jones [108] examined the surface of Hercules AU fiber, which had been electrolytically surface treated in 10% NH4HCO3, for nitrogen and a typical negative ToF-SIMS is shown in Figure 12.48. Work undertaken by Jones at Sheffield University investigating the surface constituents of RK30 sized carbon fiber is shown in Figures 12.49 and 12.50. 

Drzal and Madhukar [54] undertook the detailed measurement of the properties of AU-4 (untreated), AS-4 (treated) and AS-4C (treated and sized) carbon fiber/epoxy composites to evaluate the effect of fiber/resin adhesion (Table 20.21). 

Sizing carbon fiber with compatibie thermopiastic poiymer size... 

The presently used micron-sized carbon fibers contain at least 90% carbon and are produced by heat treatment or controlled pyrolysis of different precursor fibers. The... 

Figure 10.2 Molecular structures of polymeric precursors for micron-size carbon fibers.

Micron-sized carbon fibers are synthesized from phenolic resin fibers such as Kynol [27]. The carbon fibers prepared are typically in an activated form, which produces well-developed mesopores for use in applications as high-surface area... 

Mayer, C. and Stadtfeld, H., Continuous production of prepregs from sized carbon fiber reinforcement, DE patent 19734417 (Cl), 1998. 

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