Heating of dry samples to a higher temperature of 170 °C was trialled. After only 10 minutes of heating to this temperature, the MeOTf-initiated sample had undergone 10 mol-% degradation to DTO, while the BF3•Et2O-initiated comparator remained intact following the same treatment (Table , entries 4, 5) These experiments confirmed the formation of DTO as main product upon heating of dry samples and the large influence of the initiator on the thermal stability. We thus hypothesised that the observed difference in thermal stability was related to the different ω end groups (as the BF3•Et2O-and MeOTf-initiated samples featured comparable SEC-measured Mn values of 5.2 and 8.7 kg/mol, respectively, and comparable dispersities of 1.81 and 1.66, respectively). Indeed, the breakage of an ω end cap is typically the starting point for depolymerization. The lower thermal stability of the MeOTf-initiated polymers suggested the presence of benzyl triflate end groups compared to the less labile hydroxy end groups expected for BF3•Et2O-initiated polymers. The presumed mechanism of this thermal degradation involved a forward-biting of thioester sulfur lone pairs starting from the ω end group (Scheme 3, Pathway 4). Presumably, the counterion (hydroxide, triflate) or other nucleophiles (adventitious water) can interrupt the depolymerization by eliminating a cyclic DTO cation (Scheme 3, Pathway 4 right) which would explain the observation of partially degraded chains (Figure ) (as opposed to a mixture of fully degraded and intact chains). Notably, the dependence of the thermal stability on the nature of the ω end group remarkable. While this concept has recently been demonstrated for radically-made polymers our work demonstrates the first example of a cationic initiator influencing the thermal depolymerization efficiency and offers the possibility of tuning the degradation behaviour of a, otherwise identical, material simply through the choice of initiator.