Bibenzoate copolyesters and methods to produce them

A copolyester, comprising:

• a diol component comprising from about 10 to 90 mole percent ethylene glycol and from about 90 to 10 mole percent 1,4-cyclohexanedimethanol, based on the total moles of the diol component in the copolyester;
• and
• a diacid component comprising 4,4′-biphenyl dicarboxylate and 3,4′-biphenyl dicarboxylate, wherein the diacid component comprises from about 50 to 80 mole percent of the 4,4′-biphenyl dicarboxylate and from about 50 to 20 mole percent of the 3,4′ biphenyl dicarboxylate, based on the total moles of the diacid component in the copolyester;
• an essentially amorphous morphology;
• and
• a glass transition temperature equal to or greater than about 110° C. determined by differential scanning calorimetry (DSC) analysis from a second heating ramp at a heating rate of 10° C./min;
• optionally from about 0.05 to 0.5 mole percent of a branching agent, based on the total moles of repeating units in the copolyester.

A copolyester, comprising:

• a diol component comprising from about 10 to 90 mole percent ethylene glycol and from about 90 to 10 mole percent 1,4-cyclohexanedimethanol, based on the total moles of the diol component in the copolyester;
• and
• a diacid component comprising 4,4′-biphenyl dicarboxylate and 3,4′-biphenyl dicarboxylate, wherein the diacid component comprises from about 50 to 90 mole percent of the 4,4′-biphenyl dicarboxylate and from about 50 to 10 mole percent of the 3,4′ biphenyl dicarboxylate, based on the total moles of the diacid component in the copolyester;
• a semicrystalline morphology;
• a melting temperature of less than or equal to 250° C., determined by differential scanning calorimetry (DSC) analysis from a second heating ramp at a heating rate of 10° C./min;
• and
• a glass transition temperature equal to or greater than 120° C. determined by DSC analysis.

A method, comprising:

• contacting (i) a diol component comprising ethylene glycol and 1,4-cyclohexanedimethanol, with (ii) a diacid component comprising 4,4′-biphenyl dicarboxylic acid or ester producing equivalent thereof and 3,4′-biphenyl dicarboxylic acid or ester producing equivalent thereof, in the presence of (iii) a catalyst;
• and
• forming a copolyester comprising the ethylene glycol, 1,4-cyclohexanedimethanol, 4,4′-biphenyl dicarboxylic acid or ester producing equivalent thereof and 3,4′-biphenyl dicarboxylic acid or ester producing equivalent thereof;
• wherein the diol component in the copolyester comprises ethylene glycol and from about 10 to 90 mole percent 1,4 cyclohexanedimethanol, based on the total moles of the diol component in the copolyester;
• wherein the diacid component in the copolyester comprises from about 50 to 90 mole percent of 4,4′-biphenyl dicarboxylate, and from about 50 to 10 mole percent of 3,4′ biphenyl dicarboxylate, based on the total moles of the diacid component in the copolyester;
• wherein the copolyester has an essentially amorphous morphology and a glass transition temperature equal to or greater than about 110° C. determined by differential scanning calorimetry (DSC) analysis from a second heating ramp at a heating rate of 10° C./min;
• or
• wherein the copolyester has a semicrystalline morphology, a melting temperature of equal to or less than 250° C., determined by DSC analysis from a second heating ramp at a heating rate of 10° C./min, and a glass transition temperature equal to or greater than 120° C. determined by DSC analysis from a second heating ramp at a heating rate of 10° C./min.

A method to control the morphology, glass transition temperature, melting temperature and/or toughness of a copolyester, comprising:

• contacting (i) a diacid component comprising from about 50 to 90 mole percent 4,4′-biphenyl dicarboxylic acid or ester producing equivalent thereof, from about 50 to 10 mole percent 3,4′-biphenyl dicarboxylic acid or ester producing equivalent thereof, based on the total moles of the diacid component in the copolyester, with (ii) a diol component comprising from 10 to 90 mole percent 1,4-cyclohexanedimethanol and from about 90 to 10 mole percent ethylene glycol, based on the total moles of the diol component in the copolyester, and (iii) optionally a multifunctional carboxylic acid or ester producing equivalent thereof, and if the multifunctional carboxylic acid or ester is present, in the presence of (iv) a catalyst;
• and
• selecting a proportion of the 1,4-cyclohexanedimethanol in the diol component, a proportion of the 4,4′-biphenyl dicarboxylic acid or ester producing equivalent thereof in the diacid component, and a proportion of the multifunctional carboxylic acid or ester producing equivalent thereof in total repeating units, to produce a copolyester comprising:
• wherein the copolyester has an essentially amorphous morphology and a glass transition temperature equal to or greater than about 110° C. determined by differential scanning calorimetry (DSC) analysis from a second heating ramp at a heating rate of 10° C./min;
• or
• wherein the copolyester has a semicrystalline morphology, a melting temperature of equal to or less than 250° C., determined by DSC analysis from a second heating ramp at a heating rate of 10° C./min, and a glass transition temperature equal to or greater than 120° C. determined by DSC analysis from a second heating ramp at a heating rate of 10° C./min.