Modification of CHDM-based Polyesters with Other Glycols and Acids

9 MODIFICATION OF CHDM-BASED POLYESTERS WITH OTHER GLYCOLS AND ACIDS 

Although the scope of this review mainly covers CHDM-based polyesters modified with isophthalic acid or ethylene glycol (i.e. PCTA or PCTG, and PETG, respectively), many other copolyesters with interesting properties have been prepared with a variety of other comonomers. 

1 CHDM-BASED COPOL YESTERS WITH DIMETHYL 2,6-NAPHTHALENEDICARBOXYLATE 

All cycloaliphatic polyesters have been prepared from CHDM and 1,4-cyclohex-anedicarboxylic acid (CHDA). Dimethyl 1,4-cyclohexanedicarboxylate (DMCD) is the ester intermediate in the synthesis of CHDM and is the precursor to CHDA. 1,4-cyclohexanedicarboxylic acid is a commercially produced monomer that has 

The properties of PCTA-type structures where the modifying acid is 1,4-cyclohexanedicarboxylic acid (CHDA) have also been studied [53], The incorporation of this diacid (95 % trans) as a polyester modifier maintains the toughness, but is accompanied with significant lowering of the Tg. This is contrasted to NDA modification where the Tg is enhanced but toughness is decreased. A comparison of the properties of various PCTAs versus an amorphous PCT sample, prepared by quenching, are shown in Table 7.5. 

1 CHDM-BASED COPOLYESTERS WITH DIMETHYL 2,6-NAPHTHALENEDICARBOXYLA TE 

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