Graft copolymer, process for producing the graft copolymer, process for preparing a gel polymer electrolyte including the graft copolymer, and intermediate copolymer of the graft copolymer

A graft copolymer comprising a backbone polymer and a branched-chain polymer, and represented by formula (I),

• where:
• A is represented by X1n and is independently of each repeating unit, in which n is an integral not less than zero, and X1 is represented by
• and is independently of each repeating unit, in which
• D1 is a carbon atom or a silicon atom,
• R1 and R2 are independently —CH3, H, or F when D1 is a carbon atom, and are independently —CH3, -phenyl, —OCH3, or —OC2H, when D1 is a silicon atom, and
• m is 1 or 2;
• B is represented by
• in which
• D2 is a carbon atom or a silicon atom,
• R3, R4, R5, R6, R7, and R are independently —CH3, H, or F when D2 is a carbon atom, and are independently —CH3, -phenyl, —OCH3, or —OC2H5 when D2 is a silicon atom,
• p is 1 or 2,
• q is an integral not less than 1,
• Z1 is
• in which R15 and R16 are independent for each repeating unit, R15, R16, and R17 are independently H or alkyl, and r, s, and t are each an integral not less than 1, and
• Z2 is
• in which R18 and R19 are independent for each repeating unit, R18, R19, and R20 are independently H or alkyl, and u, v, and w are each an integral not less than 1;
• Ra, Rb, Rc, Rd, Re, and Rf are independently H or alkyl;
• k is an integral not less than 1;
• and
• G1, G2, G3, and G4 are independent for each repeating unit, and G1, G2, G3, G4, Y1, and Y2 are independently H, alkyl, or a polymer chain selected from the group consisting of polyacrylonitrile and a derivative thereof, polyvinylsulfonic acid and a derivative thereof, polyacrylate and a derivative thereof, and polyvinylphosphonic acid and a derivative thereof.