Fireproof properties

Aryloxyphosphazene copolymers can also confer fireproof properties to flammable materials when blended. Dieck [591] have used the copolymers III, and IV containing small amounts of reactive unsaturated groups to prepare blends with compatible organic polymers crosslinkable by the same mechanism which crosslinks the polyphosphazene, e.g. ethylene-propylene and butadiene-acrylonitrile copolymers, poly(vinyl chloride), unsaturated urethane rubber. These blends were used to prepare foams exhibiting excellent fire retardance and producing low smoke levels or no smoke when heated in an open flame. Oxygen index values of 27-56 were obtained. 

FRs are chemicals that can inhibit ignition and/or reduce the burning rate of a product. These are often used by manufacturers to help them meet fire safety standards set down by law for products such as electrical equipment, furnishings, and vehicles. These compounds are added to polymers, paint, textiles, and other materials to improve their fireproof properties. The main applications are in plastic housings of electronic products such as TV sets and computers, car parts, circuit boards, electric components, and cables. There are currently over 100 different substances used as FRs and these can be classihed in four categories (Figure 31.1) ... 

Donskoi and co-workers [54] showed that each of the components of a chlorosulfonated polyethylene (CSPE) mix has its own influence on the fireproofing properties and chemical processes that occur. In this case, the thermal properties of the vulcanisates of CSPE were studied, and also the heat flows from the flame on the surface of the specimen. It was established that the thermooxidative breakdown of CSPE and vulcanisates based on it during heating under dynamic conditions, is a multi-stage process. The results of tests involving various fillers and plasticisers made it possible to create rubber-like, high-impact resistant materials. 

Moreover, pyridinic nitrogen (it was reported that ammonia evolving from APP reacts with carbon-carbon double bonds to yield nitrogenated heterocycles) is observed at all temperatures in the case of zeolite and only up to 350°C in the case of a system without zeolite. It was proposed that the delay in condensation of the polyaromatic network allows the retention of pyridinic nitrogen to participate in improvement in the mechanical properties and therefore to improvement in the fireproofing properties of the material. 

Plant Fireproofing. There is a growing practice in the chemical industry of locating principal equipment out of doors and to enclose only a control room where all instmments and control equipment are centered. The control room should be resistant to potential explosion, fire, and toxicity ha2ards of processes in the vicinity. Prompt and ordedy shutdown of processes following a serious incident is essential in order to minimise personnel-injury and property-loss ha2ards (65,66). 

Cementitious materials use a hydraulically setting cement such as Portland cement as a binder with a filler material of good insulation properties, e.g., verminculite, perlite, etc. Concrete us frequently used for fireproofing because it is easily installed, readily available, is quite durable and generally economical compared to other methods. It is heavy compared to other materials and requires more steel to support that other methods. 

Table 3.15 shows some example properties of fireproofed grades. These examples are not exhaustive and indicated limits concern only a few grades. Other data can be found relating to other grades. 

The early patent disclosures have claimed the application of a wide spectrum of gas-evolving ingredients and phosphorus-based organic molecules as flame retarding additives in the electrolytes. Pyrocarbonates and phosphate esters were typical examples of such compounds. The former have a strong tendency to release CO2, which hopefully could serve as both flame suppressant and SEI formation additive, while the latter represent the major candidates that have been well-known to the polymer material and fireproofing industries.The electrochemical properties of these flame retardants in lithium ion environments were not described in these disclosures, but a close correlation was established between the low flammability and low reactivity toward metallic lithium electrodes for some of these compounds. Further research published later confirmed that any reduction of flammability almost always leads to an improvement in thermal stability on a graphitic anode or metal oxide cathode. 

Fireproofing is a fire resistant material or system that is applied to a surface to delay heat transfer to that surface. Fireproofing, a form of passive fire protection, protects against intense and prolonged heat exposure that can cause the weakening of steel and eventual collapse of unprotected equipment, vessels, and supports and lead to the spread of burning liquids and substantial loss of property. The primary purpose is to improve the capability of equipment/struc-... 

Each type of fire proofing system uses a different combination of materials with various physical and chemical properties. Selection of fireproofing materials... 

Besides the use which is made of the property of non-conduction in architecture, there are other departments of the arte and manufactures In which it subserves important purposes. Thus it fe applied with good effect in constructing fireproof edifices or apartments, and in the manufacture of chcste and boxes intended to preserve valuable property, legal documents, et cetera, from the destructive effects of conflagration. 

It is upon the property which clay possesses of being converted by heat into a firm compact mass, no longer influenced by the action of water, that ite employment in the preparation of bricks and vessels of various kinds depends and with a view to this object the different varieties of clay have been classified into fireproof, fusible, calcareous, and ferruginous—the calcareous being those which effervesce considerably with acids from containing a large proportion of earthy carbonates, particularly lime, while the ochry or ferruginous clays contain much oxide of iron, and possess a red-brown color. 

A fireproof safe is constructed of loosely packed asbestos contained between thin sheets of stainless steel. The safe is built in the form of a cube with inside and outside dimensions of 0.5 and 1.0 m. If the safe is initially uniform in temperature at 30°C and the outside is suddenly exposed to a convection environment at 600°C, h = 100 W/m2 °C, calculate the time required for the inside temperature to reach 150°C. Assume the inside surface is insulated, and neglect the resistance and capacitance of the stainless steel. Take the properties of asbestos as k = 0.16 W/m °C, a = 3.5 x 10 7 m2/s. 

Fiber wetting, in relation to antistatic propertie.s (567, Table 40), is obtained by additives constituted by the Mannich bases of phosphomus acid, which also serve as fireproofing agents. -" ... 

The lamp black apparatus consists of a cast-iron pan that holds the liquid feedstock, which is surmounted by a fireproof flue hood lined with refractory bricks. The air gap between the pan and the hood, as well as the vacuum present in the system, help to regulate the air supply and thus enable the manufacturer to fine-tune the carbon black s ultimate properties. Though radiant heat from the hood causes the raw material to vaporize and partially combust. Most of it is converted into carbon black. 

Oxidative coupling was used for the synthesis of some stabilizers having properties of AO or FR. Products of oxidation of 4,4 -isopropylidenebis(2-methyl-6-tert-butylphenol with pota ium ferricyanide [151] or of 4,4 -thiobis(2-rcr/-butyl-5-methylphenol) with oxygen in the presence of copper salts [152] (118) were tested as AO. Thermostable fireproofing additives containing 1 to 4 bromine atoms on a phenolic moiety and designed for the stabilization of thermoplastics, e.g. 119, were prepared by oxidative coupling of brominated phenols [153]. 

CHEMICAL PROPERTIES combustible solid stable and fireproof will attack some forms of plastics, rubber and coatings no incompatibilities reported FP (220°C, 428°F) LFL/UFL (NA) AT (NA). 

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