Phenolic-graphite composites

CompositGS. There has been substantial progress in improving the processability of phenolics in composite materials (104-106) to the point where a variety of materials are available for pultrusion, filament winding, and resin-transfer molding (see Composites, Fabrication). More complicated composite systems are based on aramid and graphite fibers. 

The water liberated during the cure has no apparent effect on the composite properties. Glass-filled composites prepared in this manner retain mechanical properties at elevated temperatures as well as solvent and flammability resistance (108,109). Phenolic-graphite-fiber composites that exhibit superior mechanical properties have also been prepared by this process. 

Yin, Q., Li, A., Wang, W. et al. 2007. Study on the electrical and mechanical properties of phenol formaldehyde resin/graphite composite for bipolar plate. Journal of Power Sources 165 717-721. 

Sljuldc B, Banks CE, Crossley A, Cranpton RG (2007) Lead (IV) oxide-graphite composite electrodes application to sensing of ammonia, nitrite phenols. Anal Chim Acta 587 240-246... 

One typical example of carbon/carbon composite plates is that made by Oak Ridge National Laboratory (ORNL) in the United States [12]. The composite preform was fabricafed by a slurry-molding process from fhe mixed slurry befween short carbon fibers (graphite fibers were also added in some sample plates) and fhe phenolic resin. The mass rafio between fiber reinforcement and phenolic matrix is 4 3. The phenolic matrix improves the mechanical properties and dimensional stability of the plate. A subsequent vacuum molding process was utilized to fabricate composite plates and fluid fields with relatively high resolution (Figure 5.3, [11]). 

Carbon Composites. Cermet friction materials tend to be heavy, thus making the brake system less energy-efficient. Compared with cermets, carbon (or graphite) is a thermally stable material of low density and reasonably high specific heat. A combination of these properties makes carbon attractive as a brake material and several companies are manufacturing carbon fiber—reinforced carbon-matrix composites, which are used primarily for aircraft brakes and race cars (16). Carbon composites usually consist of three types of carbon carbon in the fibrous form (see Carbon FIBERS), carbon resulting from the controlled pyrolysis of the resin (usually phenolic-based), and carbon from chemical vapor deposition (CVD) filling the pores (16). 

Westlane Plastics (USA) [45] uses an extrusion method to produce rods of up to 31.75 mm diameter, stri K, pipes with 9.52-12.7 mm wall thickness and other profile artides from compositions based on phenol, melamine, carbamide, and alkyd resins. Fillers used incluse wood crush, cellulose, chalk, talc, clay, mica, silica, coke, graphite, and carbon fibers. 

Phenols Amperometric tyrosinase biosensor based on a composite graphite-Teflon electrode modified with gold nanoparticles 3-20 nM 10... 

Autoignition of epoxy and phenolic composites with glass fiber, aramid and graphite was affected by the oxygen concentration to a limited degree. But with epoxy composites, neither fiber type nor concentration of oxygen had an effect on the autoignition time ( 50 s). In phenolic composites, the fiber type affected... 

A large diffusion may be found also for composite materials, carbon, or metal based. In the first case different types of polymeric resins (thermoplastics, such as polypropylene, polyethylene, and PVDF, or thermosettings, such as epoxies and phenolics) are filled with carbonaceous powders (graphite or carbon blacks), to provide a material characterized by very high chemical stability in the fuel cell environment and satisfactory properties of electrical conductivity, but which cannot offer sufficient robustness at thickness lower than 2 mm. The metal composite plates are essentially based on combinations (sandwiches of different layers) of stainless steel, porous graphite, and polycarbonates, with the aim to exploit the characteristics of different materials. Their fabrication can be more complex but this is compensated by the possibility to incorporate other functional components, such as manifolds, seals, and cooling layers. 

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