A Facile and Unprecedented Route to a Library of Thermostable Formaldehyde-Derived Polyesters: Highly Active and Selective Copolymerization of Cyclic Acetals and Anhydrides.
Angew Chem Int Ed Engl
; 61(13): e202117316, 2022 03 21.
Article
in En
| MEDLINE
| ID: mdl-35040252
ABSTRACT
The development of new strategies for producing polyesters can expand the category of biodegradable materials. Here, we disclose the alternating copolymerization of cyclic acetals (made from formaldehyde and diols) and anhydrides for the first time, using 5 cyclic acetals and 9 anhydrides to afford 45 unprecedented polyesters. At a wide range of reaction temperatures (25 to 140 °C), diverse metal-free Lewis/Brønsted acids are highly active catalysts for these copolymerizations via the cationic mechanism. Of interest, kinetic studies indicate that the copolymerization of cyclic acetals and anhydrides shifts the chemical equilibrium of "cyclic acetals â polyacetals" to the left, thus yielding polyesters with up to >99 % alternating degree. The obtained polyesters possess high oxygen content ([O] [C] up to 6 7), molecular weights of 2.0-33.3â
kDa, narrow polydispersities of 1.2-1.5, low glass transition temperatures (-64 to -27 °C), as well as high decomposition temperatures (275 to 324 °C).
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polyesters
/
Anhydrides
Language:
En
Journal:
Angew Chem Int Ed Engl
Year:
2022
Document type:
Article
Affiliation country:
China