Aromatic Polyester Polyols from Bottom Residues Resulting in DMT Fabrication

1 Aromatic Polyester Polyols from Bottom Residues Resulting in DMT Fabrication [4, 6,10,11] 

The bottom residues from DMT fabrication are benzyl and methyl esters of dicarboxylic and tricarboxylic acids with biphenyl or triphenyl structures together with DMT [4, 6. By the transesterification reactions of these complex ester residues with diethyleneglycol (DEG), aromatic polyester polyols with a functionality in the range 22-23 OH groups/mol are obtained. 

The product of transesterification with DEG has a complex structure (reactions 16.1 and 16.2). 

Generally, these residues from DMT fabrication are difficult to transport and are used on-site to be transformed into aromatic polyester polyols by transglycolysis [4]. Excellent rigid polyester polyols are obtained from pure DMT (reaction 16.1). 

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