Properties and Characteristics

Vitreous carbon loam is produced in several pore sizes, usually described as number of pores per inch (ppi). Commercially available foams are respectively 60,100, and 200 ppi (24,39 and 78 pores per cm). These foams have low density, with relatively even pore distribution. Their properties are listed in Table 6.4.i i 

Vitreous-carbon foam is very susceptible to oxidation due its large surface area. Any application involving an oxidizing atmosphere above 500°C should not be considered. 

Electrodes. Its chemical inertness, its wide range of usable potential (1.2 to -1.0 V vs. SCE) and the hydrodynamic and structural advantages of its open-pore foam structure make vitreous carbon foam an attractive material for electrodes for lithium-ion and other types of batteries, with many potential applications in electrochemistry.[ l[ ll ] 

Hlgh Temperature Thermal Insulation. A potential application of vitreous-carbon foam is high-temperature thermal insulation in vacuum or non-oxidizing atmosphere. Severai factors combine to make this structure an exceiient thermal insulator (a)Vne low volume fraction of the solid phase, which limits conduction (b) the small cell size, which virtually eliminates convection and reduces radiation through repeated absorption/reflection at the cell walls and (c) the poor conductivity of the enclosed gas (or vacuum). An additional advantage is its excellent thermal-shock resistance due to its 

Adsorption of Hydrocarbons and Other Gases. In the activated form, vitreous-carbon foam could replace activated-carbon granules without the requirement of a container (see Ch. 10, Sec. 4.0). Potential uses are in emission control and recovery. 

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The silanols formed above are unstable and under dehydration. On polycondensation, they give polysiloxanes (or silicones) which are characterized by their three-dimensional branched-chain structure. Various organic groups introduced within the polysiloxane chain impart certain characteristics and properties to these resins. 

The resin must be of highest purity for optimum processing characteristics and properties. Degradation results in discoloration, bubbling, and change in melt flow rate. 

Most tanks store Hquid rather than gases or soHds. Characteristics and properties such as corrosiveness, internal pressures of multicomponent solutions, tendency to scale or sublime, and formation of deposits and sludges are vital for the tank designer and the operator of the tank and are discussed herein. Excluded from the discussion are the unique properties and hazards of aerosols (qv), unstable Hquids, and emulsions (qv). A good source of information for Hquid properties for a wide range of compounds is available (2). 

There are a few excellent books dealing with the characteristics and properties of fillers. Two of the most interesting are Handbook of Fillers and Reinforcements for Plastics [37] and Handbook of Fillers [38]. 

Table 4 Cure Characteristics and Properties of Unmodified Blends...

Interstate pipelines also use computer simulation programs to calculate pipeline capacity, pressures, horsepower, fuel and other physical characteristics and properties of their systems. Using this information and incorporating variables such as ambient temperatures, facility outages, and changes in market patterns, transmission companies can run daily studies to determine how much natural gas their systems will deliver under expected operating conditions. 

It is the prediction of performance in its broadest sense, including all the characteristics and properties of materials that are essential and relate to the processing of the plastic. To the designer, an example of a strict definition of a design property could be one that permits calculating product dimensions from a stress analysis. Such properties obviously are the most desirable upon which to base material selections. 

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