Modified conjugated diene-based polymer, method for preparing the same and rubber composition including the same

A modified conjugated diene-based polymer, comprising:

• a first chain consisting of a repeating unit derived from a conjugated diene-based monomer or a repeating unit derived from a conjugated diene-based monomer and a repeating unit derived from an aromatic vinyl-based monomer;
• a second chain consisting of a repeating unit derived from a compound represented by the following Formula 1, or the repeating unit derived from the compound represented by the following Formula 1 and a derived unit from a conjugated diene-based monomer;
• and
• a derived unit from an alkoxysilane-based modifier,
• wherein the first chain and the second chain are coupled by the derived unit from the alkoxysilane-based modifier:
• in Formula 1,
• R11a and R11b are each independently a single bond, a substituted or unsubstituted alkylene group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group of 5 to 20 carbon atoms, or a substituted or unsubstituted arylene group of 6 to 20 carbon atoms, wherein the substituted
• R11a and R11b are substituted with an alkyl group of 1 to 10 carbon atoms, a cycloalkyl group of 5 to 10 carbon atoms, or an aryl group of 6 to 20 carbon atoms,
• R11c is an alkyl group of 1 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, a heteroalkyl group of 1 to 20 carbon atoms, a heteroalkenyl group of 2 to 20 carbon atoms, a heteroalkynyl group of 2 to 20 carbon atoms;
• a cycloalkyl group of 5 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, or a heterocyclic group of 3 to 20 carbon atoms, and
• R11d to R11g are each independently an alkyl group of 1 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an alkynyl group of 2 to 20 carbon atoms, a heteroalkyl group of 1 to 20 carbon atoms, a heteroalkenyl group of 2 to 20 carbon atoms, a heteroalkynyl group of 2 to 20 carbon atoms, a cycloalkyl group of 5 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms;
• a heterocyclic group of 3 to 20 carbon atoms, or a mono-substituted, di-substituted or tri-substituted alkylsilyl group with alkyl groups of 1 to 10 carbon atoms.