Polymerization of six-membered propylene oxalate

• Published in: European polymer journal 2024-11, Vol.220, p.113410, Article 113410
• Main Authors: Iakimov, Nikolai P., Budynina, Ekaterina M., Berkovich, Anna K., Serebryakova, Marina V., Platonov, Vadim B., Fomin, Evgenii O., Buyanovskaya, Anastasia G., Mikheev, Ivan V., Melik-Nubarov, Nikolay S.
• Format: Article
• Language: English
• Subjects: Cyclic oligomers; Cyclic oxalates; Polyoxalates; Propylene oxalate; Ring-opening polymerization; Tin(II) octoate
• ISSN: 0014-3057
• DOI: 10.1016/j.eurpolymj.2024.113410

[Display omitted] •Cyclic propylene oxalate is polymerized by ROP with high yield (96 %) at 100 °C.•ROP obeys the first order kinetics and tin(II) octoate accelerates it 2000 times.•ROP results in formation of linear polymers and about 10 % of cyclic oligomers.•Tin(II) octoate is partially transformed into tin oxalate via chain cross-linking.•The hydroxyl-containing initiator is incorporated into the polymer. Ring-opening polymerization (ROP) of the six-membered cyclic propylene oxalate was studied for the first time. The reaction proceeded with a high limiting conversion of about 96 % at 100 °C in the presence of tin(II) octoate. Linear macromolecules, Mw of 20–30 × 103, Р∼ 2, represented 86 % of the product, 4 % came from the equilibrium concentration of monomer, while the rest 10 % were cyclic oligomers consisting of 3–10 repeat units. ROP was accompanied by partial (about 30 %) conversion of the catalyst into the insoluble tin(II) oxalate in the course of polymer cross-linking reaction. The kinetics of polymerization obeyed first-order law, indicating typical for ROP constant number of active centers during the process. Polymerization without catalyst was 2000 times slower and also resulted in formation of polymer with Ð ∼ 2. Addition of benzyl alcohol to the polymerization mixture resulted in its inclusion into linear macromolecules and a decrease in their molecular weight. The results point to the possibility of synthesizing propylene oxalate block copolymers using macroinitiators with hydroxyl end groups.