The DSC thermograms are plotted in Figure . Tg = 24 °C and 27 °C for Poly(EA1-alt-EA2) and Poly(EA2-alt-EA1) respectively, indicating that the addition order of the two amines Ai (i = 1 or 2), does not impact the thermal properties of the polymer significantly. Moreover, Tg = 25 °C for Poly(EA1-ran-EA2), suggesting that the thermal properties of these PHUs are essentially dependent on the structure of the diamine residues and almost independent of the sequence regularity. This was also the case for the sequenced-controlled PHUs derived from the symmetric spiro bis(six-membered cyclic carbonate) of Ousaka and Endo. 34 The DSC thermograms of Poly(TA1-alt-TA2), Poly(TA2-alt-TA1), and Poly(TA1-ran-TA2) are plotted in Figure . Again, the heat capacity difference at Tg, ∆Cp, is much smaller than those of their EDC-analogs, suggesting an impact of the regioregularity on the intra-and the inter-molecular interactions of the polymers. Moreover, contrarily to their EDC-analogs, there is a clear influence of the addition order of the amines onto the Tg of the sequence-controlled polymers. Indeed, Tg = 10 °C and 20 °C for Poly(TA1-alt-TA2) and Poly(TA2-alt-TA1) respectively. This result suggests that the positioning of the amine surrogate as compared to the primary hydroxyl groups, (OH)I, essentially generated during step 2, has an impact on the Tg of the polymers. Figure recaps the nature of the neighboring (OH) groups of the Ai and the Aj segments respectively, as a function of the addition order of the diamines, for both EDC and TDC. For TDC, when Aj = A2 (step 2), the oxygen of the ether linkages of A2 can easily interact with the pendant (OH)I, via hydrogen bonding as depicted in Figure . Therefore, there is an increase of the number of intra-molecular interactions, at the expense of the intermolecular arrangements. This can lead to a decrease of the Tg. On the contrary, when Ai =A2 (step 1), the intra-molecular distance between (OH)I and the ether linkages increases. In this case, the closest (OH) neighbors of A2 are the hindered secondary hydroxyl groups generated during step 1, (OH)II, which are less accessible to develop hydrogen bonding with the ether linkages of A2. When EDC is used, instead of TDC, there are much less (OH)I generated during step 2. This might explain why the addition order of the amine has less impact on the Tg of the polymers in this case. In the end, this last result suggest that it is possible to tune the thermal properties of these sequenced-controlled PHUs by playing both with their sequence-and regioregularity.