The selective functionalization of saturated hydrocarbons. Part 40. Aspects of FeII based peroxide fragmentation in pyridine solution
摘要:
The Haber-Weiss mechanism does not apply to the Fe-II induced fragmentation of primary and secondary hydroperosides in pyridine. However, it does apply to tertiary hydroperoxides. Steric bulk is an important factor in Fe-II induced dialkyl peroxide decomposition in pyridine. On the contrary in tetrahydrofuran a different relatively unhindered electron transfer process predominates where the Fe-II becomes a catalyst. (C) 1997 Elsevier Science Ltd.
Tri-liquid system in the synthesis of dialkyl peroxides using tetraalkylammonium salts as phase-transfer catalysts
作者:Stefan Baj、Agnieszka Siewniak
DOI:10.1016/j.apcata.2010.07.015
日期:2010.9.15
system using tetraalkylammonium salts as phase-transfercatalysts is reported. This process was conducted in the presence of highly concentrated aqueous KOH solutions and cyclohexane as an organic solvent. In a liquid–liquid–liquid system, the phase-transfercatalyst forms an insoluble third-liquid phase between the organic and aqueous phases that enables the catalyst to be recycled multiple times.
A composition comprising (i) 98 to 99.8 percent by weight of a crosslinkable, semiconducting sticky elastomer, and (ii) 0.2 to 2.0 percent by weight of an organic peroxide blend containing 70 to 90 percent by weight of a eutectic bis(alpha-t-butyl peroxyisopropyl)benzene and 10 to 30 percent by weight of a peroxide, which peroxide is liquid at minus 10 to plus 25 degrees Celsius.
There is described a low number average molecular weight (MN<10 kD) and high glass transition temperature (>75° C.) copolymer (optionally a solid grade oligomer (SGO)) that comprises (a) at least 20 wt-% of itaconate functional monomer(s), (b) not more than 40% of a hydrophilic monomer, preferably an acid functional monomer(s) in an amount sufficient to achieve an acid value from 65 to 325 mg KOH per g of solid polymer; (c) optionally not more than 70% of other monomers not being either (a) or (b), having a max content of vinyl aromatic monomer(s) of 40 wt-% and/or max content of methacrylate(s) of 40 wt-%; where the weight percentages of monomers (a), (b) and (c) are calculated as a proportion of the total amount of monomers in the copolymer being 100%.