Chain end-group selectivity using an organometallic Al(iii)/K(i) ring-opening copolymerization catalyst delivers high molar mass, monodisperse polyesters

Journal article

Polyesters are important plastics, elastomers and fibres; efficient and selective polymerizations making predictable, high molar mass polymers are required. Here, a new type of catalyst for the ring-opening polymerization (ROCOP) of epoxides and anhydrides combines unusually high chain end-group selectivity, fast rates, and good molar mass control. The organometallic heterodinuclear Al(iii)/K(i) complex, applied with a diol, is tolerant to a range of epoxides/phthalic anhydride and produces only α,ω-hydroxyl telechelic polyesters with molar masses from 6-91 kg mol^-1, in all cases with monomodal distributions. As proof of its potential, high molar mass poly(vinyl cyclohexene oxide-<i>alt</i>-phthalic anhydride) (91 kg mol^-1) shows 5× greater flexural strain at break (<i>ε</i> _b = 3.7%) and 9× higher maximum flexural stress (<i>σ</i> _f = 72.3 MPa) than the previously accessed medium molar mass samples (24 kg mol^-1). It is also enchains phthalic anhydride, vinyl cyclohexene oxide and ε-decalactone, <i>via</i> switchable catalysis, to make high molar mass triblock polyesters (81 kg mol^-1, <i>Đ</i> = 1.04). This selective catalyst should be used in the future to qualify the properties of these ROCOP polyesters and to tune (multi)block polymer structures.

Authors: Diment, WT; Williams, CK

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Chemical Science
• Volume: 13
• Issue: 29
• Pages: 8543-8549
• Place of publication: England
• Publication date: 2022-07-13
• Acceptance date: 2022-06-10
• DOI: 10.1039/d2sc02752f
• EISSN: 2041-6539
• ISSN: 2041-6520
• Pmid: 35974772
• Language: English
• Keywords: FFR