PHO-diol was prepared from native PHO by transesterification reaction with BDO. The synthetic route for this oligomer is shown in Figure , according to a previous protocol . In a two-neck round-bottom flask with a water cooler, 60 g of PHO are dissolved in diglyme (250 mL) and BDO (150 eq/OH), then magnetically stirred at 100 °C under argon until completely dissolved. The temperature is then adjusted to 160 °C. Then, DBTL (0.5 eq/OH) is added, followed by stirring under argon for 48 h. The progress of the reaction is monitored by 1 H NMR until a number-average molar mass (Mn) of around 800 g mol -1 is obtained. The reaction is then cooled down before purification. The product is dissolved in chloroform and washed three times with distilled water to remove the BDO in excess. The product is then distilled to remove traces of diglyme and water. An orange viscous oil is obtained.