Flammability Properties

TABLE 13.6 Flammability and Burning Behavior of Polysulfone, Polyethersulfone, and Polyphenylsulfone 

Specific optical density Z) at flaming condition. Thickness. 

Polysulfones exhibit excellent dielectric properties. They exhibit high dielectric breakdown strength and low dielectric constant. They also exhibit low dielectric loss. Because they are amorphous, the electrical properties such as dielectric constant and dissipation factor are stable across a wide temperature range. They are also stable over a wide frequency range. The desirable electrical properties in concert with attractive flammability properties have made polysulfones successful in many electrical and electronic insulation, business machine, and lighting applications. Polysulfone electrical properties can be found in Table 13.7. 

Following OSHA definitions, a flammable material is any liquid having a flash point below 100°F. The NFPA expands this definition by including the stipulation that the vapor cannot exceed 40 psi 

Fire and Explosion Hazards Handbook of Industrial Chemicals 

It Ls important to note that a combustible liquid at or above its flash point will behave in the same manner that a flammable liquid would in a similar emergency. As an example No.2 fuel oil when heated to a temperature of 150°F can be expected to act or react in the same way gasoline would at 50°F. In most instances, however, to reach this elevated temperature will require the introduction of an external heat source. Some common examples of combustible petroleum liquids are given in Table 7. 

It is important to note that the extinguishing techniques, controlling actions, or fire-prevention activities implemented can differ greatly depending upon which of the two categories the liquid falls in. To have the ability to categorize a liquid correctly when it is not so identified, it is only necessary to know its flash point. By definition, the flash point of a liquid determines whether a liquid is flammable or combustible. 

The categories of liquids are further subdivided into classes according to the flash point plus the boiling point of certain liquids. These divisions are summarized in Table 8, which shows that flammable liquids fall into Class 1, and combustible liquids into Classes 2 and 3. The products that are at the low end (100°F) of the Class 2 combustible-liquid group might be thought of as borderline cases. These could act very much like flammable liquids if atmospheric temperatures were in die same range. It is not a common industry practice to identify either stationary or portable (mobile) liquid containers by the class of liquid it contains. The usual practice is to label either flammable or combustible and include the required U.S. Department of Transportation placard. 

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Table 10. Physical and Flammability Properties of Silicone Foam Rubber ...

An elementary introduction to chemistry is given in Chapter 3 this serves only to provide background and for more advanced consideration reference will be necessary to specific text books, e.g. as listed in the Bibliography. A brief discussion of the relevance of physicochemical principles to hazard identification is given in Chapter 4. Relevant toxic and flammable properties, and summaries of appropriate precautions to cater for them during handling, use and disposal, are provided in Chapters 5 and 6, respectively. Reactive hazards are discussed in Chapter 7. The special problems with cryogenic materials and chemicals under pressure, typified by compressed... 

In Great Britain the COSHH Regulations cover virtually all substances hazardous to health. (Excluded are asbestos, lead, materials dangerous solely due to their radioactive, explosive, or flammable properties, or solely because of high or low temperatures or pressures, or where risk... 

Fan, general-purpose A fan used to handle air that will not affect its working life, i.e., with no special requirements for temperature, moisture, or corrosive, abrasive, or flammable properties. 

The term liquefied petroleum gas (LPG) is often used to describe those liquefied flammable gases that are derived from petroleum. The term LFG is preferred when the discussion applies to all liquefied flammable gases. It includes materials such as ethylene oxide, vinyl chloride, and methylamines, which behave similarly so far as their flashing and flammable properties are concerned. 

The flammability properties of the hydrophilic PU foam developed in USA in the late 1970 s were outstanding even under severe fire conditions but it s physical properties and high densities restricted its use for other than highly specialised high risk areas. 

Figure 6-2 Relationships between various flammability properties.

Table 4.6 Flammability properties of paraffin hydrocarbons (at 25 °C, 1 atm where relevant)...

FIG. 23-3 The relationship between the various flammability properties. (D. A. Cro-wl and J. F. Louvar, Chemical Process Safety Fundamentals with Applications, 2d ed, 2002. Adapted by permission of Pearson Education, Inc., Upper Saddle River, N.J.)... 

Operating pressure There are three modes of operation of a quench tank atmospheric pressure operation, nonvented operation, and controlled venting operation. Atmospheric operation is usually feasible when the effluent Being emitted has a bubble point well above the maximum ambient temperature. A very small quantity of vapor escapes with the air that is displaced as the tank fills with the emergency discharge (typically about 0.2 percent of the reactor contents). Depending on the toxic or flammable properties of the vapor, the vent from the quench tank can be routed to the atmosphere or must be sent to a scrubber or flare. 

Kashiwagi T, Grulke E, Hilding J, Harris R, Awad W, Douglas J (2002). Thermal degradation and flammability properties of poly(propylene)/carbon nanotube composites. Macromol. Rapid Commun. 23 761-765. 

Hydrogen is a stable gas in seclusion, but in air, is very unstable. The flammability properties of such a mixture are well-known at atmospheric pressure, yet little is known about the hydrogen-air mixture at sub-atmospheric pressures. In order to determine the hydrogen reaction limits within a vacuum, a number of experiments were performed and analyzed. The results were used to design a vacuum furnace system and processes with safeguards to protect against a severe hydrogen reaction. 

Flammability properties of materials are clearly important for fire prevention but there are other properties that are also significant. There have been a number of severe fire incidents initiated by a material s reactivity properties that were previously unrecognized or unknown to the user. The development of a Materials Hazard Identification program requires knowledge of a material s toxicity and reactivity, as well as flammability. 

Note 2 Fillers may be added to modify mechanical, optical, electrical, thermal, flammability properties, or simply to serve as extenders. 

Gilman JW, Bourbigot S, Shields JR et al. (2003) High throughput methods for polymer nanocomposites research extrusion, NMR characterization and flammability property screening. J Mat Sci 38 4451... 

Gilman JW, Davis RD, Shields JR et al. (2004) Development of high-throughput methods for polymer flammability property characterization. International SAMPE Symposium and Exhibition 460-469... 

Additional research to find a suitable carrying agent having low explosive and flammability properties is urgently needed as we increase the control of adult mosquitoes by fogs and sprays dispersed by the new types of applicators. 

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