The polymerization of M1 was initiated using A as the initiator across various solvents. The conversion of M1 reached only 49%, with size exclusion chromatography (SEC) revealing a number-average molecular weight (Mn) of 36.4 kg/mol and distribution (Đ) of 1.26 (Table , entry 1). Both the conversion and Mn were elevated under identical conditions (Table , entries 2 and 3). An increased temperature of 180 °C resulted in a reduced conversion of M1 to 47% (Table , entry 4). This decrease could potentially be attributed to the thermal desulfonylation of sulfonyl radical intermediates, which interrupts chain propagation. Subsequently, initiation conditions utilizing B and C were examined. The polymer obtained exhibited a high Mn of 61.4 kg/mol, although the conversion was comparable to that achieved with the A system at 66% (Table , entry 5). Remarkably, the B system achieved nearly complete conversion of M1, producing a polymer with an increased Mn of 82.3 kg/mol (Table , Entry 6). With an elevation of temperature to 160 °C, the polymerization maintained high efficiency, but with a slight decrease in Mn and an increase in Đ to 2.00 (Table , Entry 7). Under the conditions of entry 6, kinetic studies showed that this GTPR process can generate a high Mn product at the beginning, and the Mn keeps at a high level when the conversion reaches 80% (Fig. ), consistent with the characteristics of fast chain propagation in free radical polymerization.