Diol compound, polycarbonate, and preparation method of the same

A polycarbonate, comprising a diol compound of the following Chemical Formula 1, a compound of the following Chemical Formula 2, and a repeating unit derived from a carbonate precursor:

• wherein in Chemical Formula 1:
• R is a divalent group derived from benzene, unsubstituted biphenyl, terphenyl, or naphthalene;
• C3-20 cycloalkylene unsubstituted or substituted with C1-10 alkyl;
• or C3-20 heterocycloalkylene unsubstituted or substituted with C1-10 alkyl, and
• n and m are each independently an integer from 1 to 1,000,
• wherein in Chemical Formula 2:
• R1 to R4 are each independently hydrogen, C1-10 alkyl, C1-10 alkoxy, or halogen;
• and
• Z is C1-10 alkylene unsubstituted or substituted with phenyl, C3-15 cycloalkylene unsubstituted or substituted with C1-10 alkyl, O, S, SO, SO2, or CO.

A method of preparing a polycarbonate, comprising a step of polymerizing a composition containing a compound of the following Chemical Formula 1, an aromatic diol compound of the following Chemical Formula 2 and a carbonate precursor:

• wherein in Chemical Formula 1:
• R is a divalent group derived from benzene, unsubstituted biphenyl, terphenyl, or naphthalene;
• C3-20 cycloalkylene unsubstituted or substituted with C1-10 alkyl;
• or C3-20 heterocycloalkylene unsubstituted or substituted with C1-10 alkyl;
• and
• n and m are each independently an integer from 1 to 1,000,
• wherein in Chemical Formula 2:
• R1 to R4 are each independently hydrogen, C1-10 alkyl, C1-10 alkoxy, or halogen;
• and
• Z is C1-10 alkylene unsubstituted or substituted with phenyl, C3-15 cycloalkylene unsubstituted or substituted with C1-10 alkyl, O, S, SO, SO2, or CO.