Process For Preparing A High Molecular Weight Heteroaromatic Polyester Or Copolyester

Abstract

A process for preparing a high molecular weight heteraromatic polyester or copolyester is disclosed. A process for preparing a high molecular weight heteroaromatic polyester or copolyester includes the steps of: (a) processing comonomers by mixing together to form a homogeneous solution (1) at least one heteroaromatic dicarboxylic acid having 2-12 carbon atoms or a diester or an acid anhydride derived therefrom, or a mixture thereof; (2) at least one alcohol having 2 to 12 carbon atoms and at least two hydroxyl functionalities; and (3) optionally aromatic or aliphatic dicarboxylic acids or diesters or acid anhydrides derived therefrom; (b) converting the paste/solution obtained in step a) into an esterification product containing at least one diester or at least one oligoester formed from the at least one heteroaromatic dicarboxylic acid and the at least one alcohol; and (c) polycondensing/copolycondensing the reaction product obtained from step b) under reduced pressure.

What is claimed is: 
     
         1 . A high molecular weight heteroaromatic polyester or copolyester comprising:
 a) between about 50 mol % to about 100 mol %, based on the sum total of feed dicarboxylic acids, of a heteroaromatic dicarboxylic acid; and   b) at least one diol component selected from the group consisting of ethylene glycol, propanediol, and 1,4-butanediol;   wherein the high molecular weight heteroaromatic polyester or copolyester is prepared by a process comprising the steps of:   a) processing comonomers by mixing together to form a paste or by mixing under elevated temperature to form a homogeneous solution:
 at least one heteroaromatic dicarboxylic acid having 2-12 carbon atoms or a diester or an acid anhydride derived therefrom, or a mixture thereof; 
 at least one alcohol having 2 to 12 carbon atoms and at least two hydroxyl functionalities; and 
 optionally further aromatic or aliphatic dicarboxylic acids or diesters or acid anhydrides derived therefrom; 
   b) converting the paste/solution obtained in step a) into:
 b 1 ) an esterification product, the esterification product containing at least one diester or at least one oligoester formed from the at least one heteroaromatic dicarboxylic acid or an acid anhydride derived therefrom and the at least one alcohol; or 
 b 2 ) a transesterification product, the transesterification product containing at least one diester or at least one oligoester formed from a diester and the at least one alcohol; and 
   c) polycondensing/copolycondensing the reaction product obtained from step
 b) under reduced pressure compared with standard conditions; 
   wherein:
 step c) further comprises:
 step c 1 ) obtaining a polyester prepolymer/copolyester prepolymer by polycondensation/copolycondensation from the reaction product obtained from step b); and 
 step c 2 ) obtaining the polyester/copolyester from the polyester prepolymer/copolyester prepolymer of step c 1 ) by polycondensation/copolycondensation; 
 
 the esterification/transesterification product of step b) contains the diester in an amount of about 20 to about 98 wt %; 
 the reaction product formed in step b) is standardized to an intrinsic viscosity (I.V.) in the range of about 0.05 dL/g to about 0.10 dL/g. 
   
     
     
         2 . The polyester or copolyester of  claim 1 , wherein the polyester or copolyester contains between about 50% and about 99% carbon atoms accessible from renewable sources, based on the sum total of all carbon atoms, consisting of monomers selected from the group consisting of: biobased 2,5-furandicarboxylic acid, biobased succinic acid, biobased adipic acid, biobased sebacic acid, biobased ethylene glycol, biobased propanediol, biobased 1,4-butanediol, biobased isosorbide, and biobased lactic acid. 
     
     
         3 . The polyester or copolyester of  claim 1 , wherein the polyester or copolyester is biodegradable to EN 13432 and contains at least one heteroaromatic dicarboxylic acid in an amount in the range of about 40 to about 60 mol %, and at least one aliphatic dicarboxylic acid in an amount in the range of about 60 to about 40 mol% based on the sum of all dicarboxylic acids used.