Solvent Applications of Short-Chain Oxymethylene Dimethyl Ether Oligomers

Abstract

Short-chain oxymethylene dimethyl ethers (OMEs) (molecular formula: H3CO–(CH2O) n –CH3, where n = 3–5) have previously been studied as diesel-like fuels and fuel additives. OMEs can be produced from sustainably sourced methanol, and tests indicate that they are neither genotoxic nor mutagenic. In this report, their potential as solvents has been investigated to expand the bio-derived solvent space. According to traditional solvatochromic parameters, a commercial mixture of OME3–5 and its individual components (OME3, OME4, and OME5) have solvation properties similar to problematic industrial ether solvents such as 1,4-dioxane. Peroxide formation, one of the chief dangers of classical ether solvents, was found to occur much more slowly in OMEs than in conventional solvents such as tetrahydrofuran (THF), demonstrating an improved safety profile. The commercial OME3–5 mixture was found to be broadly miscible with organic solvents but immiscible with water, suggesting potential application in aqueous extractions. It performed well in the dissolution of polystyrene and removal of paints and coatings, indicating OME3–5 may suitable to replace dichloromethane in polymer recycling, polymer welding, and cleaning applications. To further demonstrate applicability as a solvent, this mixture was shown to facilitate a model Suzuki coupling reaction at rates similar to cyclopentyl methyl ether, which is currently marketed as a green ether. Finally, OME3–5 proved a suitable solvent for enzymatic polymerization, giving high yields, moderately high degrees of polymerization, and remarkably narrow dispersity values.

Polymer Chemistry Applications of Cyrene and its Derivative Cygnet 0.0 as Safer Replacements for Polar Aprotic Solvents

“…The collected data fit the trends observed for the synthesis of the same adipate‐based polymers in OMEs and DPE. Again the most successful polymers synthesized were the ODO‐based ones, reaching M n / M w of 7400/9700 g mol −1 and 10400/13600 g mol −1 when the syntheses were carried out in OMEs and DPE, respectively [55] . The difference in the recovered yields is most probably due to shorter polymer chains being more soluble in the nonsolvent (ice‐cold methanol) and therefore are lost during the precipitation and washing steps.…”

“…Again the most successful polymers synthesized were the ODO‐based ones, reaching M n / M w of 7400/9700 g mol −1 and 10400/13600 g mol −1 when the syntheses were carried out in OMEs and DPE, respectively. [55] The difference in the recovered yields is most probably due to shorter polymer chains being more soluble in the nonsolvent (ice‐cold methanol) and therefore are lost during the precipitation and washing steps. This observation, together with the lower obtained molecular weights, is consistent with the reactions between dimethyl adipate and various diols that were carried out in a solvent‐less reaction system; in fact, also, in this case, the C 4 BDO led to polymers having slightly lower molecular weights ( M n / M w =6600/11500 g mol −1 ) in comparison with the reactions carried out using the C 6 and C 8 diols ( M n / M w =6700/13700 g mol −1 for C 6 and 7100/12600 g mol −1 for C 8 , respectively).…”

Synthesis of tailored oxymethylene ether (OME) fuels via transacetalization reactions

“…Dimethoxymethane (DMM, methylal, OMDME 1 ) is the most known compound in this series and it is used predominantly as a solvent. [19][20][21] Fuel properties of DMM have been investigated extensively and engine tests have been carried out. [22][23][24][25] It is also used for the synthesis of higher molecular weight OMEs, e.g.…”

Multi-Step Enzymatic Synthesis of 1,9-Nonanedioic Acid from a Renewable Fatty Acid and Its Application for the Enzymatic Production of Biopolyesters

“…The enzymatic synthesis of polyesters and polyamides from biomass-derived monomers was extensively investigated with increasing attention as an eco-friendly approach for producing sustainable materials from renewable resources, and reducing greenhouse gas emissions and carbon footprint [24,25,26,27,28]. For instance, a series of bio-based alternatives based on 2,4-, 2,5-, and 2,6-pyridinedicarboxylic acid-derived polymers were produced via enzymatic catalysis [25].…”