Polycarbonate ester and preparation method therefor
A method for preparing a polycarbonate ester includes feeding a monomer mixture containing (i) at least one compound selected from the group consisting of compounds of the following Formulae 1 and 3; (ii) a compound of the following Formula 2; and (iii) a 1,4:3,6-dianhydrohexitol to a polycondensation reactor and allowing the monomers and the 1,4:3,6-dianhydrohexitol to react to prepare the polycarbontate ester. The prepared polycarbonate ester has improved mechanical properties including tensile strength and impact strength:
1. A process for preparing a polycarbonate ester, which comprises:
feeding a monomer mixture comprising (i) at least one compound selected from the group consisting of compounds of the following Formulae 1 and 3; (ii) a compound of the following Formula 2; and (iii) a 1,4:3,6-dianhydrohexitol to a reactor comprising one or more stirrers, said reactor being an extruder, a kneader, or a finisher reactor;
melting the monomer mixture and reacting the monomer mixture at a reduced pressure to prepare a polycarbonate prepolymer; and
further reacting the polycarbonate prepolymer at a reduced pressure to prepare the polycarbonate ester;
wherein the polycarbonate prepolymer has an intrinsic viscosity (IV) of 0.10 to 0.60 dl/g:
wherein in Formula 2, R 1 and R 2 are each an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms,
wherein the aryl group may have at least one substituent selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 4 to 20 carbon atoms, an aryl group having 6 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a cycloalkoxy group having 4 to 20 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, a cycloalkylsulfonyl group having 4 to 20 carbon atoms, an arylsulfonyl group having 6 to 18 carbon atoms, and an ester substituent; and the ester substituent may be an alkyl ester having 1 to 18 carbon atoms, a cycloalkyl ester having 4 to 20 carbon atoms, or an aryl ester having 6 to 18 carbon atoms,
wherein the polycarbonate ester has an intrinsic viscosity (IV) of 0.8 to 2.3 dl/g, and
wherein a specimen injection-molded according to ASTM D638 test method from the polycarbonate ester has a tensile strength of 80 to 200 MPa and a flexural strength of 100 to 210 MPa.
2. The process of claim 1 , wherein the step of melting is carried out at 20 to 700 mbar and 140 to 220° C.
3. The process of claim 1 , wherein the step of further reacting is carried out at 0.1 to 20 mbar and 220 to 270° C.
4. The process of claim 1 , wherein polycarbonate ester has an Izod notch impact strength of 60 J/m to no breakage.