Spontaneous alternating copolymerization of isobutoxyallene with 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione

The spontaneous copolymerization of isobutoxyallene (1) with 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione (2) was carried out to afford a copolymer with a number‐average molecular weight of 5900–10,300. The copolymer consisted of a 2,3‐polymerization unit of 1 and a NN polymerization unit of 2, maintaining an alternating character regardless of the monomer feed ratio. The corresponding copolymerization of 1 with 2 in the presence of methanol afforded the adduct of the compounds without the polymer, indicating the generation of a zwitterion of 1 and 2.