EO ( Ethylene Oxide )

Catalog	ACMA00030951
Description	We market Pure Ethylene Oxide (PEO) to several customers spread across diverse end-use segments.
Application	PEO is used in the manufacture of Ethoxylates, Ethanolamines, PEGs, Glycol Ethers & Drug Intermediates.

Case Study

N-Heterocyclic Carbene Induced Ring-Opening Polymerization of Ethylene Oxide

Raynaud, Jean, et al. Journal of the American Chemical Society, 2009, 131(9), 3201-3209.

In the absence of any other reagents, N-heterocyclic carbene (NHC) [1,3-bis-(diisopropyl)imidazol-2-methylene] can initiate metal-free ring-opening polymerization of ethylene oxide in dimethyl sulfoxide at 50 °C. Studies have shown that NHC adds to ethylene oxide to form zwitterionic species, i.e., 1,3-bis-(diisopropyl)imidazol-2-methylene alkoxide, which then further grows via a zwitterionic ring-opening polymerization (ZROP) mechanism. By choosing appropriate terminators NuH or NuSiMe3 at the completion of polymerization, various end-functionalized PEO chains can be generated.
Synthesis of r,ω-Difunctionalized Poly(ethylene oxide)s.
· In a typical procedure, 2 mL of a 10-1 M solution of NHC 1 (2 × 10-4 mol) was injected via syringe into a vacuumed flame-dried Schlenk maintained in a glovebox under an argon atmosphere.
· Upon removing the Schlenk from the glovebox, 15 mL of dry DMSO was added under vacuum. Following thorough mixing, 1 mL (5 × 10-2 mol) of EO was added at -20 °C. The Schlenk was allowed to warm to room temperature and placed in a thermostatted oil bath at 50 °C for 3 days. The color changed to orange within a few minutes, indicating the presence of an imidazolium alkoxide.
· Three equivalents of an appropriate terminating agent (deionized H2O, N3SiMe3, or PhCH2OH) relative to NHC were then added. The color turned pale yellow, and the reaction mixture was stirred overnight. The DMSO solution was precipitated in a large excess of diethyl ether at room temperature. The polymer was dissolved in dichloromethane, precipitated twice in diethyl ether, and collected as a white powder that was dried under vacuum.

Synthetic Strategies for PEO-containing Triblock Terpolymers from Ethylene Oxide

Markus J. Barthel, et al. Polym. Chem., 2014, 5, 2647-2662.

Polyethylene oxide (PEO) is a versatile building block that has attracted wide attention for its solubility, nontoxicity, and biocompatibility. Common synthetic strategies for PEO-based triblock terpolymers are listed here:
· For ethylene oxide (EO), living anionic ring-opening polymerization (AROP) is usually the method of choice for controlling molar mass and very narrow molar mass distribution. Polyether-based ABC triblock terpolymers can be synthesized by sequential monomer addition of glycidyl ethers. An example is poly(ethylene oxide)-block-poly(allyl glycidyl ether)-block-poly(tert-butyl glycidyl ether) (PEO- b-PAGE-bP(t-BGE)).
· It is also possible to transform the OH end-group of PEO with, e.g., 2-bromoisobutyryl bromide to obtain a macroinitiator for atom transfer radical polymerization (ATRP). This has already enabled the synthesis of poly- (ethylene oxide)-block-poly(2-hydroxyethyl methacrylate)-blockpoly(tert-butyl acrylate) (PEO-b-PHEMA-b-PtBA) triblock terpolymers.
· The functionalization of PEO with an alkyne moiety for the use in copper mediated 1,3-cycloaddition reactions with an azide functionalized PtBA counterpart has been demonstrated. The [4 + 2] cycloadditions (Diels-Alder reactions) can be used, e.g., to form ABC triblock terpolymers. A synthetic route combining AROP, click chemistry, and Diels-Alder chemistry to synthesize PEO-b-PS-b-PMMA has been developed.