Fire-retardant properties

The reaction with sodium sulfite or bisulfite (5,11) to yield sodium-P-sulfopropionamide [19298-89-6] (C3H7N04S-Na) is very useful since it can be used as a scavenger for acrylamide monomer. The reaction proceeds very rapidly even at room temperature, and the product has low toxicity. Reactions with phosphines and phosphine oxides have been studied (12), and the products are potentially useful because of thek fire retardant properties. Reactions with sulfide and dithiocarbamates proceed readily but have no appHcations (5). However, the reaction with mercaptide ions has been used for analytical purposes (13)). Water reacts with the amide group (5) to form hydrolysis products, and other hydroxy compounds, such as alcohols and phenols, react readily to form ether compounds. Primary aUphatic alcohols are the most reactive and the reactions are compHcated by partial hydrolysis of the amide groups by any water present. 

A key property associated with chlorinated paraffins, particularly the high chlorine grades, is nonflammability, which has led to their use as fire-retardant additives and plasticizers in a wide range of polymeric materials. The fire-retardant properties are considerably enhanced by the inclusion of antimony trioxide. 

Plasticized PVC. Chlorinated paraffins are employed as secondary plasticizers with fire-retardant properties in PVC and can be used as partial replacements for primary plasticizers (qv) such as phthalates (1) and phosphate esters (2). 

Where fire retardancy is of importance, then reference should be made to Tables 5.13-5.15, which will indicate the intrinsic fire retardancy of the polymer. It will, however, be noted that many polymers may be modified to enhance fire retardancy properties so that fire retardant grades of such polymers may be considered. It is to be noted that such enhanced fire retardancy may be associated with adverse effects on other properties. 

Primary plasticizers may be further subdivided. The phthalate types me by far the most popular due to cost and ease of incorporation. Dioctyl phthalate and diisooctyl phthalate are typical of this class, They exhibit good general -purpose properties. Phosphate plasticizers are also important for general-purpose use. Typical of these are tritolyl phosphate and trixylenyl phosphate. These plasticizers also impart fire retardant properties. Low-temperature plasticizers, such as dibntyl sebacate, are used where good low-temperature flexibility is required, For maximum... 

Table I shows that, of all the pigments tested, zinc borate showed the best fire-retardant properties. Calcium carbonate showed valuable retardant properties, its effectiveness increasing with increased concentration. This would indicate that it functions by decomposition with subsequent release of /carbon dioxide.

Examination of Table II will show that, of all the vehicles tested, the alkyd resins produced the best fire-retardant properties. All these films were air-dried at room temperature in the absence of any catalysts other than lead and cobalt where appropriate. 

Of the pigments and extenders tested, zinc borate is the most effective as a fire retardant. Calcium carbonate has good fire-retardant properties, especially in the limitation of the char area. Antimony oxide, whether in presence or absence of chlorine, is not particularly effective as a fire-retardant pigment in paint. 

Pigment volume concentration has a definite etrect on fire-retardant properties of paint films. This effect appears to be specific for each pigment or pigment combination. 

The total sales of mirex by Hooker Chemicals and Plastics Corporation, in the United States between 1959 and 1975, were around 1,528,000 kg (Kaiser, 1978). Among the total sales of mirex, 26% was for insecticidal use and 76% was for other uses, such as the incorporation of mirex into plastics to improve flame- and fire-retardant properties (Kaiser, 1978). Between 1961 and 1975, 400,000kg of mirex were used as pesticides, of which approximately 250,000 kg were sold in the south eastern United States for the control of native and imported fire ants (Solenopsis spp.) and most of the remainder was exported to Brazil for use in fire ant control (Eisler, 1985). 

From Table 1, we can see that bark components do possess many of the above inherent fire retardant features. Thus the fire retardant properties obtained should not have been a surprise but rather an expected result which I can attribute to the design of the components used. 

In conclusion, I have attempted to demonstrate that bark can be used as the sole polyol component in the production of rigid polyurethane foam. These foams possess good physical as well as inherent fire retardant properties. With the availability of bark as a reactive polyol, I can see a means of utilizing bark as a cheap raw material in producing economical polyurethane foam products. 

A more recent innovation has been the development of nickel-doped forms of magnesium hydroxide, which are claimed to have superior fire-retardant properties.4... 

This is a low cost material with limited fire-retardant properties. It has a low onset of decomposition (under 100°C), but it is reported to find some use as a fire retardant in unsaturated polyester resins.7... 

An extensive study was conducted on the effect of chemical and structural aspects of zeolites on the fire performance of the intumescent system, ammonium polyphosphate-pentaerythritol (APP-PER), where a marked improvement of the fire-retardant properties within different polymeric matrices has been observed.56 58 The synergistic mechanism of zeolite 4A with the intumescent materials was investigated using solid-state NMR. Chemical analysis combined with cross-polarization dipolar-decoupled magic-angle spinning NMR revealed that the materials resulting from the thermal treatment of the APP-PER and APP-PER/4A systems were formed by carbonaceous and phosphocarbonaceous species, and that the zeolite enhances the stability of the phosphocarbonaceous species. 

Mutmansky, J.M., Brune, J.F., Calizaya, F., Mucho, T.P., Tien, J.C., and Weeks, J.L., The final report of the Technical Study Panel on the utilization of belt air and the composition and fire retardant properties of belt materials in underground coal mining, 2007. http //www.cdc.gov/niosh/mining/mineract/pdfs/... 

In this paper we report the use of some phosphine oxides, phosphonic acids, and phosphinic acids to impart fire retardant properties to polymers. In addition, we postulate a mechanism by which these compounds behave as flame retardant agents. 

In our studies we found that phosphonic acids (16), phosphinic acids (25), and phosphine oxides (17) are additives capable of imparting fire retardant properties to thermoplastic polymers. Tables I and II present data for some of these compounds when added to polyethylene or to poly (methyl methacrylate). The concentration reported is not necessarily the lowest effective concentration for the additive in the polymer. These additives also were effective in other thermoplastic polymers such as polystyrene, impact polystyrene, polypropylene and ABS. The compounds were completely compatible with the polymers. 

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