Process for preparing poly(alkylene furandicarboxylate)

A process comprising the steps:

• a) contacting a mixture comprising furandicarboxylic acid dialkyl ester, a diol comprising ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, or mixtures thereof, and a metal catalyst at a temperature in the range of from about 140° C. to about 220° C. to form prepolymer,
• wherein the mole ratio of the furandicarboxylic acid dialkyl ester to the diol is in the range of from 1:1.3 to 1:2.2;
• b) performing polycondensation by heating the prepolymer under reduced pressure to a temperature in the range of from about 220° C. to about 260° C. to form poly(alkylene furandicarboxylate) polymer;
• wherein the rate of polycondensation in step c) is faster with the anthraquinone compound present than without;
• and
• c) independently adding to step a) and/or step b) at least one anthraquinone compound represented by Structure A
• wherein each R is independently selected from the group consisting of H, OH, C1-C6 alkyl, NHCOCH3, SO2NHC6H11, and each Q, Y, and Z is independently selected from H, OH, NH2, and NHR′, wherein R′ is cyclohexyl or substituted aryl.