Phosphorous Copolymer, Method for Preparing the Same, and Flame Retardant Thermoplastic Resin Composition Including the Same

A method for preparing a phosphorous copolymer comprising a repeat unit represented by Formula 1, the method comprising:

• reacting a phosphonic dichloride compound represented by Formula 2, a dichlorophosphate compound represented by Formula 3, and a diol compound represented by Formula 4.
• wherein:
• each A is the same or different and is each independently a single bond, C1 to C5 alkylene, C1 to C5 alkylidene, C5 to C6 cycloalkylidene, —S—, or —SO2—;
• R1 and R2 are the same or different and are each independently substituted or unsubstituted C1 to C6 alkyl or substituted or unsubstituted C6 to C20 aryl;
• R3 and R4 are the same or different and are each independently substituted or unsubstituted C1 to C6 alkyl, substituted or unsubstituted C3 to C6 cycloalkyl, substituted or unsubstituted C6 to C12 aryl, or halogen;
• a and b are the same or different and are each independently an integer from 0 to 4;
• and
• m and n are the same or different and are each independently an integer from 1 to 500.
• wherein in Formulas 2 to 4, A, R1, R2, R3, R4, a and b are the same as defined in Formula 1.

The flame retardant thermoplastic resin composition comprising:

• a thermoplastic resin;
• and
• a phosphorous copolymer comprising a repeat unit represented by Formula 1:
• wherein:
• each A is the same or different and is each independently a single bond, C1 to C5 alkylene, C1 to C5 alkylidene, C5 to C6 cycloalkylidene, —S—, or —SO2—;
• R1 and R2 are the same or different and are each independently substituted or unsubstituted C1 to C6 alkyl or substituted or unsubstituted C6 to C20 aryl;
• R3 and R4 are the same or different and are each independently substituted or unsubstituted C1 to C6 alkyl, substituted or unsubstituted C3 to C6 cycloalkyl, substituted or unsubstituted C6 to C12 aryl, or halogen;
• a and b are the same or different and are each independently an integer from 0 to 4;
• and
• m and n are the same or different and are each independently an integer from 1 to 500.