Semi-Aromatic Co-Polyesters

The first patents in which isosorbide based polyesters are described are from the 1960s. Most of these were aimed at fibre applications and involved co-polyesters with terephthalic acid and other monomers [18-21]. 

3 mol% isosorbide content (30% theoretical) and Tg = 139 °C. This material approaches the range of polycarbonate (Tg 148-150 °C). Since the extensive work by DuPont and Roquette on the development of PEIT many other patent applications on PEIT and related polyesters 

Recently Bersot et al. described an improved melt polymerization method for PEIT by using antimony catalysts in combination with other metals (Al, Mg or Li) [33]. Although higher polymerization efficiency and less (but still high) colouration were achieved, the maximum incorporation of isosorbide was 20% with M values up to 9600. 

Aliphatic isohexide polyesters have been studied with various types of applications in mind. Noordover et al. described co-polyesters of succinic acid with combinations of isosor-bide/isoidide and various other diols for powder coating application [35]. Depending on 

Percentage isosorbide in feed Percentage isosorbide incorporated Tg(°Q Tm C Q Ref 

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