614. Organic carbonates. Part V. The mechanism of hydrolysis of cyclic carbonates: tracer studies

Abstract

Acid-and base-catalysed hydrolysis of carbonates of 2,2-dialkylpropane-1,3-diol in H,180 proceeds with CO-0 bond-fission a t both stages. Under both conditions oxygen exchange occurs during the hydrolysis, in all the cases studied, between the exocyclic oxygen atom and the solvent. These facts are interpreted in terms of a possibly non-cyclic intermediate in which the carbonyl-oxygen atom participates in a reversible fashion.* Formerly Shalom Israelashvili.

Ring-Opening Polymerization of Ethylene Carbonate and Depolymerization of Poly(ethylene oxide-co-ethylene carbonate)

“…The oxide sequences in the polymer backbone were converted to poly- or oligo(ethylene glycol)s; the carbonate linkage can be easily hydrolyzed ,, under basic conditions as follows: Figure shows the GPC results of the hydrolyzed polymers of case I. In the early stage of the reaction a major peak was observed at 31.8 min elution time.…”

Bioreversible Derivatives of Phenol. 2. Reactivity of Carbonate Esters with Fatty Acid-like Structures Towards Hydrolysis in Aqueous Solutions

“…The hydrogen ion catalyzed hydrolysis is thought to occur through a multistage process (A Ac 2 [53]) (Scheme 1A). A rapid preequilibrium protonation step is followed by a slow bimolecular reaction, the attack of a water molecule, and carbonyl-oxygen fission [54][55][56] and subsequently by a fast unimolecular acyl-oxygen fission of the alkyl hydrogen carbonate [55,57]. Ethyl phenyl carbonate [42] has previously been found to be subject to specific acid catalysis.…”

Incorporation ofCO2‐polyols into ester‐based waterborne polyurethane: An effective strategy to improve overall performance

“…The good hydrolysis properties of PPG‐modified WPU were due to the ether groups in PPG structure. The improved hydrolysis resistance of WPU modified by CO 2 ‐polyol was due to the combination of carbonate and ether groups in the backbone of CO 2 ‐polol 42–43 . The improved hydrolysis resistance of WPU modified by CO was due to the existence of hydrophobic long alkyl group in CO 44–46 …”

“…The improved hydrolysis resistance of WPU modified by CO 2 -polyol was due to the combination of carbonate and ether groups in the backbone of CO 2 -polol. [42][43] The improved hydrolysis resistance of WPU modified by CO was due to the existence of hydrophobic long alkyl group in CO. [44][45][46] The similar swelling and hydrolysis resistance properties of CO 2 -polyol or PPG modified WPU was resulted from the existence of ether group in these two materials that significantly prevented the permeation of water and consequently slowed the hydrolysis reaction of the ester group in WPU. Poor swelling behavior of CO-modified WPU might be caused by the existence of the long chain alkyl group that cannot obviously resist the swelling and hydrolysis reaction caused by degradation.…”