Flame retardant precursors, polymers prepared from such precursors, and flame resistant fabrics treated with such polymers

A composition comprising at least one condensed phosphorus compound, the condensed phosphorus compound being produced by reacting together in a condensation reaction

• (a) a nitrogen compound conforming to the structure of Formula (N)
• wherein RN1 is selected from the group consisting of an oxygen atom, a sulfur atom, and a N—H group, and RN2 and RN3 are independently selected from the group consisting of hydrogen, hydrocarbyl groups, substituted hydrocarbyl groups, acyl groups, and silyl groups;
• and
• (b) a phosphonium compound conforming to the structure of Formula (P)
• wherein the variable a is a positive integer;
• each R1 is selected from the group consisting of hydrogen, C1-C3 alkyl groups, C1-C3 haloalkyl groups, C2-C3 alkenyl groups, and C2-C3 haloalkenyl groups;
• X is an anion selected from the group consisting of halides, sulfate, hydrogen sulfate, phosphate, acetate, carbonate, bicarbonate, borate, and hydroxide;
• b is a negative integer representing the charge of the anion X;
• and a is equal to (−b);
• wherein the nitrogen compound and the phosphonium compound are reacted together in a ratio of 1 to 3 molar equivalents of nitrogen compound to 1 molar equivalent of phosphonium cations;
• and
• wherein about 30 mol. % or less of the condensed phosphorus compounds contained in the composition comprise moieties conforming to the structure of Formula (B)