Containing phosphorus oxygen index

Table 1. Oxygen Index of PET Fibers Containing Phosphorus or Bromine Flame Retardants ...

The residue after combustion increases considerably from 5.2% for the un-modified resin to 30% for the one containing 1.05% of phosphorus. The oxygen index changes from 19 for the un-modified resin to 22.4 for Jthe one containing 1.47% of phosphorus. 

Also phosphorus- and nitrogen-containing polyols are shown to be effective in flame retardancy of PU foams24 such as polyols based on phosphonic acid ester or obtained by partial or full substitution of methylol groups of tetrakis(hydroxymethyl)phosphonium chloride with amine several examples of such polyols were reported by Levchik and Weil.15 Rigid PU foam modified with these polyols showed improved oxygen index values moreover better results were achieved with higher functionality polyols. 

Polycarbonate exhibits a relatively high oxygen index of 26. It may be further flame retarded by the addition of flame-retardant additives, including tetrabromo-BPA polymer, oligomer, or other bromi-nated additives, alkali metal salts,polytetra-fluoroethylene, phosphorus-containing additives, or silicones.Glass fillers or other inert fillers may also provide improved performance in Underwriters Laboratories (UL) flame testing. 

Paraffins can be separated from mixtures with other solvents almost quantitatively by using a mixture of 170 parts of 85% phosphoric acid (q = 1.7) and 100 parts of concentrated sulfuric acid (q = 1.84). Oxygen-containing compounds dissolve, and hydrocarbons remain undissolved in this mixture. Only some reactive olefins can partly form monoesters of sulfuric acid. The process is carried out with cooling, and the reduction in the volume of the upper layer, as well as the change of its refractive index, are followed. The procedure can be considered as completed when both the volume and the refractive index become constant. If a mixture of sulfuric acid and phosphorus pentoxide is used, olefins and aromatic compounds also react, so that enly paraffins remain undissolved (1). 

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