Ring-Opening Copolymerization of Maleic Anhydride with Epoxides: A Chain-Growth Approach to Unsaturated Polyesters

Abstract

We report the ring-opening copolymerization of maleic anhydride with a variety of epoxides catalyzed by a chromium(III) salen complex. Quantitative isomerization of the cis-maleate form of all polymers affords the trans-fumarate analogues. Addition of chain transfer reagents yields low M(n), narrow PDI polymer samples. This method provides access to a range of new unsaturated polyesters with versatile functionality, as well as the first synthesis of high molecular weight poly(propylene fumarate).

Ring-opening copolymerization (ROCOP): synthesis and properties of polyesters and polycarbonates

“…Shortly after, Coates reported the successful use of cobalt and chromium salen complexes, 6a and 6b, for epoxide-MA copolymerizations. 17 Unusually, complexes 6a/6b were effective, but slow initiators without any co-catalysts (TOF = 6 h À1 and 13 h À1 for 6a and 6b, respectively, at 45 1C, in toluene). Poly(propylene maleate) (PPM) of relatively high molecular weight was produced (M n = 5000 g mol À1 ; 17 000 g mol À1 , 6a and 6b, respectively).…”

“…The (BDI)ZnOAc complex shows low activity (TOF o 1 h À1 ) for MA-PO copolymerization to afford polymers with high ether linkages (86%). 17 2.3.3 Metal salen and salan complexes. Metal(III) salen complexes ( Fig.…”

“…17 The T g of the poly(alkylene maleate) was tuned from À26 1C to 41 1C by simply changing the epoxide co-monomer. The highest T g was observed using perfluoro alkyl substituted epoxides, whilst epoxides with diethylene glycol substituents afforded materials with the lowest T g .…”

Tandem catalysis: a new approach to polypeptides and cyclic carbonates

“…2). 30,35 This type of Lewis base cocatalyst reversibly coordinates to the metal centre, increases the electron density on the metal, and labilizes the trans ligand to it. 36 As a control experiment, the ROP of 25 equiv.…”

Alternating copolymerization of CHO and MA catalyzed by the hetero-bimetallic Zn-Yb-Salen complex

“…Since the precedent milestone on the catalytic coupling of propylene oxide (PPO) and MA [6], the copolymerized epoxide monomers are extended to aromatic epoxides [7], and the catalyst systems are proceeded from unstable metal alkoxides [8] to stable porphyrinato- [9], Salenbased [10] or asymmetric Salen-analogous M(III) complexes [11]. In this context, from the viewpoint of "green" synthesis, the bulk solvent-free copolymerization procedure, together with the development of low toxicity catalysts are much deserved.…”