Method for preparing highly transparent and highly heat-resistant polycarbonate ester

A method for preparing a bio-based polycarbonate ester comprising a repeating unit of Formula 1, comprising the steps of:

• (1) subjecting a reaction mixture comprising a compound of Formula 2 and a halogenation agent to convert the compound of Formula 2 into an intermediate reactant of Formula 2a and then subjecting the intermediate reactant of Formula 2a to a nucleophilic reaction with phenol to yield a diphenyl ester of Formula 3;
• and
• (2) subjecting the diphenyl ester of Formula 3 prepared in step (1), a compound of Formula 4, and 1,4:3,6-dianhydrohexitol to a polycarbonate melt polycondensation reaction to yield the bio-based polycarbonate ester comprising the repeating unit of Formula 1:
• wherein
• R is methyl or hydrogen,
• R1 and R2 are each independently a substituted or unsubstituted C1-C18 aliphatic group, or a substituted or unsubstituted C1-C18 aromatic group,
• R3 is F, Cl, or Br, and
• x is a real number of 0<x<1.