Polymerization of α‐methacrolein and the structure of the polymers

A high molecular weight poly(α‐methylacrolein) was obtaiiied with a yield of about 100% in the presence of a redox system and its strncture was investigated. It was established that the intrinsic viscosity of the polymers increases during the polymerization. It was shown that high molecular weight. poly(α‐methylacrolein) obtained with K2S2‐O2/AgNO3 contains not only free aldehyde groups but also the seniiacetal‐ether ones. The polymerization of α‐methyl‐ and α‐ethylacrolein was conducted with sodium naphthalene and trityl sodium. The structure of the polymers obtained was investigated by the following methods: oxinlation, ozonization, hydrogenation, oxidation with perbenzoic acid, and by PAIR and infrared spectroscopy. The dependence of the resulting structure on the temperature of the polymerization was established. It was shown that when the polymerization was conducted below 0°C. the polymers contained mainly coildensed tetrahydropyran cycles. At 0°C. and above the polymerization rate is changed, and the structure of the polymers is changed according to the data of chemical analysis, the formation of lactone structure being observed. Some considerations on the mechanism of the polymerization are given.