Synthesis of periodic copolymers via ring‐opening copolymerizations of cyclic anhydrides with tetrahydrofuran using nonafluorobutanesulfonimide as an organic catalyst and subsequent transformation to aliphatic polyesters

Abstract

To synthesize polyesters and periodic copolymers catalyzed by nonafluorobutanesulfonimide (Nf2NH), we performed ring‐opening copolymerizations of cyclic anhydrides with tetrahydrofuran (THF) at 50–120 °C. At high temperature (100–120 °C), the cyclic anhydrides, such as succinic anhydride (SAn), glutaric anhydride (GAn), phthalic anhydride (PAn), maleic anhydride (MAn), and citraconic anhydride (CAn), copolymerized with THF via ring‐opening to produce polyesters (Mn = 0.8–6.8 × 103, Mn/Mw = 2.03–3.51). Ether units were temporarily formed during this copolymerization and subsequently, the ether units were transformed into esters by chain transfer reaction, thus giving the corresponding polyester. On the other hand, at low temperature (25–50 °C), ring‐opening copolymerizations of the cyclic anhydrides with THF produced poly(ester‐ether) (Mn = 3.4–12.1 × 103, Mw/Mn = 1.44–2.10). NMR and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectra revealed that when toluene (4 M) was used as a solvent, GAn reacted with THF (unit ratio: 1:2) to produce periodic copolymers (Mn = 5.9 × 103, Mw/Mn = 2.10). We have also performed model reactions to delineate the mechanism by which periodic copolymers containing both ester and ether units were transformed into polyesters by raising the reaction temperature to 120 °C. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Heterocycle/Heteroallene Ring‐Opening Copolymerization: Selective Catalysis Delivering Alternating Copolymers

“…Adding a phosphonium co‐catalyst resulted in completely alternating polymers from 3,3′‐disubstituted oxetanes and succinic/diphenic anhydride (TOF <1 h −1 , 130 °C, 5 mol %, M n =2.9–11.1 kg mol −1 ) [109] . Alternating copolymers from anhydride/THF ROCOP were achieved with a bistriflimidic acid catalyst (TOF 3–10 h −1 , 120 °C, 1 mol %, M n =2.0–3.5 kg mol −1 ) [110] . The organoaluminium catalyst Al( i Bu) 3 also terpolymerises anhydrides, epoxides, oxetane, or THF into (ABC) n polymers [111] .…”

Zr(IV) Catalyst for the Ring-Opening Copolymerization of Anhydrides (A) with Epoxides (B), Oxetane (B), and Tetrahydrofurans (C) to Make ABB- and/or ABC-Poly(ester-alt-ethers)

“… 25 Another report describes a cationic bistriflimidic acid catalyst for THF/anhydride ROCOP, but it requires a high catalyst loading and has a low TOF (3–10 h –1 , [Cat]/[THF]/[anhydride] 1:20:20, 130 °C). 28 There is just one report, from 1973, of a tri(isobutyl)Al(III)/water catalyst system, affording, under specific conditions, ABC poly(ester- alt -ether) structures from anhydrides ( A ), epoxides ( B ), and THF ( C ). 29 Curiously, the ABC sequences only formed for reactions in excess THF, and without it, alternating AB polyesters form.…”

A Facile and Unprecedented Route to a Library of Thermostable Formaldehyde‐Derived Polyesters: Highly Active and Selective Copolymerization of Cyclic Acetals and Anhydrides

“…Epoxides generally have a high‐tension three‐membered ring that makes them possess high reactivity in their anionic copolymerizations with cyclic anhydrides [32] . By contrast, the cationic copolymerization of low‐tension tetrahydrofuran (THF) with cyclic anhydrides exhibited low activity and proceeded at high temperatures (100–120 °C) to yield polyesters with low molecular weights ( M n =0.8–6.8 kDa) and broad polydispersities ( Ð =2.0–3.5), as reported by Takasu and co‐workers [33] . Cyclic acetals are also known as low‐tension heterocyclic compounds, which have a ring larger than five‐membered and are typically (co)polymerized by the cationic route [34–36] .…”