Crosslinkable random copolymers comprising atom transfer radical polymerization (ATRP) initiators and crosslinked copolymer films formed from the copolymers are provided. The random copolymers, which are polymerized from one or more alkyl halide functional inimers and one or more monomers having a crosslinkable functionality, are characterized by pendant ATRP initiating groups and pendant crosslinkable groups.

To improve the thermal stability of a brominated polymer type flame retardant in a flame-retardant resin composition containing a styrene-based resin and the brominated polymer type flame retardant to provide a flame-retardant resin molded article in which occurrences of black foreign substances and discoloration decrease. The flame-retardant resin composition contains a styrene-based resin, a brominated polymer type flame retardant, an epoxy compound, and a halogen capture agent, wherein a content of bromine is 18 to 42% by mass.

To improve the thermal stability of a brominated polymer type flame retardant in a flame-retardant resin composition containing a styrene-based resin and the brominated polymer type flame retardant to provide a flame-retardant resin molded article in which occurrences of black foreign substances and discoloration decrease. The flame-retardant resin composition contains a styrene-based resin, a brominated polymer type flame retardant, an epoxy compound, and a halogen capture agent, wherein a content of bromine is 18 to 42% by mass.

Crosslinkable random copolymers comprising atom transfer radical polymerization (ATRP) initiators and crosslinked copolymer films formed from the copolymers are provided. The random copolymers, which are polymerized from one or more alkyl halide functional inimers and one or more monomers having a crosslinkable functionality, are characterized by pendant ATRP initiating groups and pendant crosslinkable groups.

Described herein is a composition comprising a fluorinated polysulfinic acid or a salt thereof having the following formula (I): ##STR00001##
wherein X.sub.1, X.sub.2, and X.sub.3 are independently selected from H, F, Cl, Br, I, CF.sub.3, and CH.sub.3 and wherein at least one of X.sub.1, X.sub.2, or X.sub.3 is H; R.sub.1 is a linking group; Z.sub.1 and Z.sub.2 are independently selected from Br, Cl, I, F, CF.sub.3, and a perfluorinated alkyl group; M is a cation; p is 0 or 1; and n is at least 2. Also described is a method of making the partially fluorinated polysulfinic acid or salt thereof.

Described herein is a composition comprising a fluorinated polysulfinic acid or a salt thereof having the following formula (I): ##STR00001##
wherein X.sub.1, X.sub.2, and X.sub.3 are independently selected from H, F, Cl, Br, I, CF.sub.3, and CH.sub.3 and wherein at least one of X.sub.1, X.sub.2, or X.sub.3 is H; R.sub.1 is a linking group; Z.sub.1 and Z.sub.2 are independently selected from Br, Cl, I, F, CF.sub.3, and a perfluorinated alkyl group; M is a cation; p is 0 or 1; and n is at least 2. Also described is a method of making the partially fluorinated polysulfinic acid or salt thereof.

Described herein is a method of making a fluoropolymer and fluoropolymers thereof, wherein the method comprises: (a) providing an aqueous solution comprising a water soluble polyiodide salt of Formula (I): M.sup.+y[II(I).sub.n].sub.y.sup. wherein M is a cation group having a valence y, y is an integer of at least 1 and n is an integer of at least 1; and (b) initiating polymerization of a monomer in the aqueous solution, wherein the monomer is a fluorinated monomer.

Described herein is a method of making a fluoropolymer and fluoropolymers thereof, wherein the method comprises: (a) providing an aqueous solution comprising a water soluble polyiodide salt of Formula (I): M.sup.+y[II(I).sub.n].sub.y.sup. wherein M is a cation group having a valence y, y is an integer of at least 1 and n is an integer of at least 1; and (b) initiating polymerization of a monomer in the aqueous solution, wherein the monomer is a fluorinated monomer.

A method of producing a fluorine-containing compound is a method of producing a compound (30) having partial structure (3) by an insertion reaction of compound (20) into compound (10) that has partial structure (1), in the presence of an ionic catalyst formed from a specific monovalent anion and a counter cation. In the formulas, * represents a bonding site, and X.sup.1 and R.sup.1 to R.sup.4 each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, or an organic group having a carbon number of 1 to 20 which may have a substituent. ##STR00001##