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).

Content Provider	Europe PMC
Author	Kerr, Ryan W.F. Williams, Charlotte K.
Copyright Year	2022
Abstract	Poly(ester-alt-ethers) can combine beneficialether linkage flexibility and polarity with ester linkage hydrolysability,furnishing fully degradable polymers. Despite their promising properties,this class of polymers remains underexplored, in part due to difficultiesin polymer synthesis. Here, a catalyzed copolymerization using commerciallyavailable monomers, butylene oxide (BO)/oxetane (OX), tetrahydrofuran(THF), and phthalic anhydride (PA), accesses a series of well-definedpoly(ester-alt-ethers). A Zr(IV) catalyst is reportedthat yields polymer repeat units comprising a ring-opened PA (A), followed by two ring-opened cyclic ethers (B/C) (−ABB– or −ABC−).It operates with high polymerization control, good rate, and successfullyenchains epoxides, oxetane, and/or tetrahydrofurans, providing a straightforwardmeans to moderate the distance between ester linkages. Kinetic analysisof PA/BO copolymerization, with/without THF, reveals an overall second-orderrate law: first order in both catalyst and butylene oxide concentrationsbut zero order in phthalic anhydride and, where it is present, zeroorder in THF. Poly(ester-alt-ethers) have lower glass-transitiontemperatures (−16 °C < Tg < 12 °C) than the analogous alternating polyesters, consistentwith the greater backbone flexibility. They also show faster esterhydrolysis rates compared with the analogous AB polymers.The Zr(IV) catalyst furnishes poly(ester-alt-ethers)from a range of commercially available epoxides and anhydride; itpresents a straightforward method to moderate degradable polymers’properties.
ISSN	00027863
Volume Number	144
PubMed Central reference number	PMC9084548
Issue Number	15
PubMed reference number	35388696
Journal	Journal of the American Chemical Society [J. Am. Chem. Soc]
e-ISSN	15205126
DOI	10.1021/jacs.2c01225
Language	English
Publisher	American Chemical Society
Publisher Date	2022-04-07
Access Restriction	Open
Rights License	Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). © 2022 American Chemical Society
Content Type	Text
Resource Type	Article
Subject	Chemistry Colloid and Surface Chemistry Biochemistry Catalysis