Table . Optimization of radical homopolymerization of methyl 2-cyanohept-6-enoate. Entry Initiator Solvent Conv. (%) Mn (kg/mol The structural characterization of the polymer chain was elucidated through 1 H nuclear magnetic resonance (NMR) spectroscopy. In the spectrum, the aliphatic resonance observed between 3.49-3.52 ppm was attributed to the hydrogen atoms (denoted as Hf) adjacent to the cyano and ester groups. Notably, this signal was absent in the 1 H NMR spectrum of the polymerized sample (Fig. ), indicating alterations in the chemical environment of these hydrogen atoms consequent to the polymerization process. A peak spacing (m/z = 167) that corresponds to the designated repeating unit was identified in the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis (Fig. ). As shown in Fig. , polymers with Mn of 10 kg/mol were reached even at low conversion, which indicated a typical radical polymerization process. With the optimized polymerization conditions in hand, we investigated the broader application of 1,5-HAT-mediated radical polymerization (Fig. ). The polymerization of monomer M1 was successfully scaled up to 100 grams, achieving a yield of 93%. Monomers with ethyl, n-octyl, and isopropyl ester exhibited good reactivity, achieving polymer conversions ranging from 82% to 95% (P2-P4). Furthermore, substituting with either a phosphonate or an amide group lead to the synthesis of the corresponding polymers, although with moderate conversions of 58% and 43%, respectively. When the substituents are only esters, polymers P7 and P8 were synthesized with conversions of 86% and 80%. The thermal characteristics of these polymers were characterized using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).