Phosphazene Functionalized Silsesquioxane-Based Porous Polymer as Thermally Stable and Reusable Catalyst for Bulk Ring-Opening Polymerization of ε-Caprolactone

Yuliya A Piskun; Evgenii A Ksendzov; Anastasiya V Resko; Mikhail A Soldatov; Peter Timashev; Hongzhi Liu; Irina V Vasilenko; Sergei V Kostjuk

doi:10.3390/polym15051291

Phosphazene Functionalized Silsesquioxane-Based Porous Polymer as Thermally Stable and Reusable Catalyst for Bulk Ring-Opening Polymerization of ε-Caprolactone

Polymers (Basel). 2023 Mar 3;15(5):1291. doi: 10.3390/polym15051291.

Authors

Yuliya A Piskun^{1

2}, Evgenii A Ksendzov^{1

2}, Anastasiya V Resko¹, Mikhail A Soldatov³, Peter Timashev^{4

5

6}, Hongzhi Liu⁷, Irina V Vasilenko^{1

2}, Sergei V Kostjuk^{1

2

4}

Affiliations

¹ Research Institute for Physical Chemical Problems of the Belarusian State University, 14 Leningradskaya St., 220006 Minsk, Belarus.
² Department of Chemistry, Belarusian State University, 14 Leningradskaya St., 220050 Minsk, Belarus.
³ Department of Science and Technology Projects, D. Mendeleev University of Chemical Technology of Russia, 9 Miusskaya Sq., 125047 Moscow, Russia.
⁴ Institute for Regenerative Medicine, Sechenov University, 8-2 Trubetskaya St., 119991 Moscow, Russia.
⁵ World-Class Research Center "Digital Biodesign and Personalized Healthcare", Sechenov University, 8-2 Trubetskaya St., 119991 Moscow, Russia.
⁶ Chemistry Department, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia.
⁷ Key Laboratory of Special Functional Aggregated Materials, Shandong University, 27 Shanda Nanlu, Jinan 250100, China.

Abstract

The bulk ring-opening polymerization (ROP) of ε-caprolactone using phosphazene-containing porous polymeric material (HPCP) has been studied at high reaction temperatures (130-150 °C). HPCP in conjunction with benzyl alcohol as an initiator induced the living ROP of ε-caprolactone, affording polyesters with a controlled molecular weight up to 6000 g mol^-1 and moderate polydispersity (Ð~1.5) under optimized conditions ([BnOH]/[CL] = 50; HPCP: 0.63 mM; 150 °C). Poly(ε-caprolactone)s with higher molecular weight (up to M_n = 14,000 g mol^-1, Ð~1.9) were obtained at a lower temperature, at 130 °C. Due to its high thermal and chemical stability, HPCP can be reused for at least three consecutive cycles without a significant decrease in the catalyst efficiency. The tentative mechanism of the HPCP-catalyzed ROP of ε-caprolactone, the key stage of which consists of the activation of the initiator through the basic sites of the catalyst, was proposed.

Keywords: heterogeneous catalysis; phosphazene base; porous polymeric material; ring-opening polymerization; ε-caprolactone.

Abstract

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