Xi:Irritant;19327-38-9Relevant articles and documents
Effect of chain unsaturation on the self-association of tri- and tetraethylene glycol octyl ethers obtained by butadiene telomerization
Lai, Jonathan,Molinier, Valerie,Sauthier, Mathieu,Moity, Laurianne,Castanet, Yves,Mortreux, Andre,Aubry, Jean-Marie
, p. 242 - 250 (2012)
2,7-Octadienyl ethers of tri- and tetraethylene glycol (C 8:2E3 and C8:2E4) have been synthesized by the atom-economical butadiene telomerization of the corresponding poly(ethylene glycols). On one hand, this synthetic path is attractive because it is expeditious and environmentally benign, and on the other hand, it provides unconventional amphiphiles for which the lipophilic chains possess two double bonds. These two unsaturations increase the global hydrophilicity of the compound, which is also highlighted by the modelization of the compounds using the conductor-like screening model for real solvents (COSMO-RS). The behavior of C8:2E3 and C8:2E4 in binary amphiphile/water and ternary amphiphile/oil/water systems is therefore greatly modified compared to that of the conventional fully saturated homologues (C 8E3 and C8E4) that are easily obtained after hydrogenation. This results in a lowered efficiency of the unsaturated compounds for oil solubilization. The usual Winsor-type microemulsion systems are formed, and for the same oil, the DLS investigation of the microstructure of the Winsor I microemulsion does not highlight any difference in the self-association between the unsaturated and saturated compounds.
Combinatorial synthesis of PEG oligomer libraries
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Page/Page column 9, (2010/02/15)
A simple chain-extending approach was established for the scale-up of the monoprotected monodisperse PEG diol materials. Reactions of THP-(OCH2CH2)n—OMs (n=4, 8, 12) with a large excess of commercially available H—(OCH2CH2)n—OH (n=1-4) under basic conditions led to THP-(OCH2CH2)n—OH (n=5-15). Similarly, Me-(OCH2CH2)n—OH (n=4-11, 13) were prepared from Me-(OCH2CH2)n—OMs (n=3, 7, 11). For the chain elongation steps, 40-80% yields were achieved through extraction purification. PEG oligomer libraries I and II were generated in 50-95% overall yields by alkylation or acylation of THP-(OCH2CH2)n—OH (n=1-15) followed by deprotection. Alkylation of Me-(OCH2CH2)n—OH (n=1-11, 13) with X—(CH2)m—CO2R (X=Br or OMs) and subsequent hydrolysis led to PEG oligomer library III in 30-60% overall yields. Combinatorial purification techniques were adapted to the larger-scale library synthesis. A total of 498 compounds, each with a weight of 2-5 g and a minimum purity of 90%, were synthesized.
Process for preventing consolidation of p-dichlorobenzene
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, (2008/06/13)
A triethylene glycol derivative is added to p-dichlorobenzene so as to prevent consolidation and improve flowability of p-dichlorobenzene.
