Table 2.

Influence of p-cresol equivalents on molecular weight and T_g of PIsSu

Equiv. p-cresol	Mn [kg/mol]	PDI	Tg [°C]	Unreacted isosorbide after esterification [mol%]*
0.5	28.1	2.5	81	0.8
0.9	40.3	2.7	83	1.2
1.5	40.4	2.4	82	2.0
2.2	31.6	2.0	82	2.9

Reaction conditions (unless noted otherwise): Reactions were conducted on a 60 mmol scale (respective diacid), with a 1:1 molar ratio of isosorbide:succinic acid and 0.1 mol% BuSnOOH catalyst (resp. diacid). The amount of p-cresol in each experiment was varied as indicated (respective diacid). Esterification was conducted for 5 h at 240 °C. For pre-polycondensation, the temperature was decreased to 220 °C and the pressure reduced from atmospheric pressure to 0.4–0.8 mbar within 2 h. Polycondensation was conducted for 1 h at 220 °C and 0.4–0.8 mbar.

*Determined from 1H NMR spectra after esterification, see Supplementary Information p. 5.