Isosorbide and Tricyclodecanedimethanol for the Synthesis of Amorphous and High Tg Partially Biobased Copolyesters

The synthesis and properties of amorphous poly(tricyclodecanedimethylene-co-isosorbide terephthalate) (PTIT) with the isosorbide (IS) content ranging from 0 to 68 mol % relative to the total diol amount were investigated. Surprisingly, it was found that isosorbide enhanced the polycondensation kinetics and acted as a temporary chain linker. Polymerization kinetics improvement maximum was observed when the isosorbide content was around 9 mol %. It was also found that higher molar masses were achieved when the isosorbide molar content was increased (number-average molar mass, Mn, around 16,000 g mol–1). The glass transition temperature linearly increased of 0.7 °C per mol% of isosorbide for each molar percent of isosorbide included in the polyester. The Tg values of the polyesters could be adjusted between 115 and 163 °C, depending on the isosorbide content. Their mechanical properties were investigated, and ductile properties were achieved up to 57 mol % of isosorbide. These properties are coupled with a very high heat deflection temperature (HDT).