Copolymerization Of Cyclic Anhydrides Research Articles

Alternating ring‐opening copolymerization of cyclic anhydrides and epoxides by zeolitic imidazolate framework‐67: A promising approach

The ring opening copolymerization (ROCOP) of epoxides and cyclic anhydrides is one of the most important ways to synthesize polyesters both in industrial and academic fields. Herein, the zeolitic imidazolate framework‐67 (ZIF‐67) was used as a heterogeneous catalyst for the ROCOP of epoxides and cyclic anhydrides without co‐catalyst and initiator. Notably, the obtained polyesters with alternate structures were proved by the 1H NMR spectrum and FTIR spectrum, which indicate the ROCOP is alternatively copolymerized. Kinetic study of the ROCOP of cyclohexene oxide (CHO) and phthalic anhydride (PA) shows that the polymerization reaction is first‐order kinetics. The apparent activation energy (Ea) of the ROCOP of CHO and PA catalyzed by ZIF‐67 was found to be about 104.4 KJ/mol. A possible mechanism of ROCOP of CHO and PA is that the metal Co coordinates with the oxygen atom on the monomer to weaken the C‐O bond thereby opening the ring structure and initiating the copolymerization reaction. In this study, a new system for the copolymerization of epoxide and anhydride catalyzed by heterogeneous catalysts was discovered, which has important guiding significance.

Electronic Tuning of Iminotriphenolate Ligands for Titanium(IV)‐catalyzed Ring‐opening Copolymerization of Cyclic Anhydrides and Epoxides

AbstractAlternating ring‐opening copolymerization (ROCOP) is a versatile synthetic method for preparing polyesters using relatively inexpensive and readily available monomers, epoxides and cyclic anhydrides. In this study, a new type of titanium (IV) complex coordinated with iminophenolate ligands was developed as an efficient catalyst for alternating ROCOP. As found in the crystal structures, iminophenolate titanium (IV) complexes exhibited octahedral geometries owing to geometrical constraints. Electronic tuning of iminophenolate ligands revealed that chloro‐substituted ligands are more efficient than other ligands with electron‐withdrawing or electron‐donating ligands. Density functional theory computation provided reaction profiles where octahedral intermediates and transition states were stabilized, and the chlorine substituent was the most efficient in stabilizing the transition state for the epoxide opening step.

Ring‐Opening Copolymerization of Cyclic Anhydrides and Epoxides by bis(amidinate)tin(II) Complex via Binary Catalyst System

AbstractBis(amidinate) tin(II) complex (1) was reported as active catalyst for ring‐opening copolymerization of cyclic anhydrides and epoxides via a binary catalyst system. Polymerizations of six combinations of epoxides and cyclic anhydrides were carried out giving highly alternating poly(anhydride‐alt‐epoxide) with narrow dispersities, except for cyclohexene oxide where significant amount of ether linkage up to 62 % was observed. This ether linkages could be diminished by increasing the amount of cocatalyst to over 3 equiv. Six well‐known cocatalysts were screened where PPNCl was found to be the best cocatalyst.

Modelowanie procesu kopolimeryzacji przemiennej cyklicznych bezwodnikow z epoksydami

Modelowanie procesu kopolimeryzacji przemiennej cyklicznych bezwodnikow z epoksydami

Bifunctional Aminotriphenolate Complexes as One‐Component Catalysts for the Ring‐Opening Copolymerization of Cyclic Anhydrides and Epoxides

Bifunctional aminotriphenolate complexes derived from trivalent metals (M = Co, Mn, Cr) have been prepared and structurally characterized. These complexes are octahedral in the solid state but infer dynamic behavior of the ligated dimethylaminopyridine (DMAP) ligands that can function as initiators in the ring‐opening copolymerization of cyclic anhydrides and epoxides. More specifically, the ring‐opening copolymerization of cyclohexene oxide and phthalic anhydride was studied in detail, and the bifunctional CrIII complex gave overall the best results in terms of overall activity and polyester quality.

Ring‐Opening Copolymerization of Styrene Oxide and Cyclic Anhydrides by using Highly Effective Zinc Amido–Oxazolinate Catalysts

AbstractPolyesters have been widely applied owing to their biodegradability and biocompatibility. Recently, catalytic ring‐opening copolymerization of cyclic anhydrides and epoxides has emerged as an effective approach for the synthesis of polyesters. Herein, we report a series of amido–oxazolinate zinc complexes as highly active catalysts for the ring‐opening copolymerization of styrene oxide and cyclic anhydrides. Turnover frequencies up to 4000 h−1 were achieved in the reaction of styrene oxide and maleic anhydride. Analysis of the end groups provides a useful probe for the preference at the electron‐poor methine site of styrene oxide for the ring‐opening process.

Poly(propylene succinate): a new polymer stereocomplex.

Herein we show the formation of a polymer stereocomplex by mixing isotactic, regioregular chains of poly(propylene succinate) synthesized via the copolymerization of cyclic anhydrides and epoxides. The stereocomplex exhibits significantly improved thermal properties in comparison to the enantiopure parent polymers. We demonstrate that stereocomplexation is a route to a new class of semicrystalline polyesters with improved properties, produced from readily accessible starting materials.

Crosslinking mechanism of an anhydride‐cured epoxy resin as studied by fourier transform infrared spectroscopy

AbstractFourier transform infrared spectra, including absorbance difference spectra, are presented which indicate that the accepted mechanism of tertiary amine‐catalyzed copolymerization of cyclic anhydrides and epoxy resins requires modification. Results also show that the kinetic model is complicated by the lack of steady‐state concentrations of the active species. The effect of silica filler and silane coupling agents on the reaction are also examined.