A Review of Phosphorus-Containing Flame Retardants

Abstract

The flame retardant mechanism described for phosphorus- containing flame retardants includes both a condensed and a vapor phase mechanism depending on the type of phosphorus compound and the polymer. Intumescence is also described. Chemical structures of the flame retardant are shown. Specific applications for red phosphorus, organophosphates, chlorophos phates and bromophosphates are described. The use of triarylphosphates in PVC, modified polyphenylene oxide, and polycarbonate/ABS is described. The chlorophosphates are used in polyurethanes and the bromophosphates in en gineering thermoplastics. Flammability and mechanical properties are given for specific polymers.

Synthesis and characterization of phosphorus-containing polyurethanes

“…The char yield (YD varies from 2 to 25 % for the polyurethanes with various phosphorus content and is increased with increasing the content of phenylbis(hydroxyalkyl)phosphonate (Figure 4). The higher char yield of the phosphorus-containing polyurethane is probably due to the fact that the phosphorus form anhydrides of phosphoric and the related acids which may act as dehydrating agents and promote char formation [15,16]. Figure 5 shows the DTG curves of the B series.…”

Effect of silicon and phosphorus on the degradation of polyurethanes

“…The third step differs from the degradation of the first and second steps, which may be due to the formation of a thin glassy layer or liquid protective coating of polyphosphate on the condensed phase. 34 Similarly, the T1m and T2m could not be evaluated for P-PU2 because the DTG curve presented multiabsorption peaks. Furthermore, the maximum temperatures (Tm1, Tm2, and Tm3) of the P-PU1 polymers were lower than were those of Si-PU1, which indicated that the P-PU1 polymers will degrade faster at a lower temperature.…”

Preparation of flame‐retardant leather pretreated with pyrovatex CP

“…The utilization of phosphorus compounds chemically reacted with or deposited within the leather fibers represents the most significant contribution to the field of durable flame retardancy. 1 The compound N-methylol dimethyl phosphorus propionamide, a retardant finish, has been used in the United States since 1968. 2 It has been known for over 30 years that phosphorus compounds can retard flame in cellulosic textiles.…”