摘要:
Polyoxyalkylene glycol monoesters of carboxylic acids are prepared by a process in which tetrahydrofuran or a mixture of tetrahydrofuran with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals is polymerized in the absence of water and in the presence of a carboxylic acid and of an anhydrous heteropolyacid catalyst.
摘要:
Polyoxyalkylene glycol monoethers of monohydric alcohols are prepared by a process in which tetrahydrofuran or a mixture of tetrahydrofuran with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals is polymerised in the absence of water and in the presence of a monohydric alcohol and of an anhydrous heteropoly acid catalyst.
摘要:
Polyoxyalkylene glycols are prepared by a process in which tetrahydrofuran is polymerized with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals in the absence of water and in the presence of a monohydric alcohol or of a monocarboxylic acid with the aid of an anhydrous heteropoly acid catalyst, and the polyoxyalkylene glycol is liberated from the resulting polyoxyalkylene glycol monoethers or polyoxyalkylene glycol monoesters by cleavage of the monoether or monoester bond.
摘要:
Polyoxyalkylene glycol monoethers of monohydric alcohols are prepared by a process in which tetrahydrofuran or a mixture of tetrahydrofuran with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals is polymerized in the absence of water and in the presence of a monohydric alcohol and of an anhydrous heteropoly acid catalyst.
摘要:
The average molecular weight of polyoxyalkylene glycols and polyoxyalkylene glycol derivatives is adjusted in the heteropolyacid-catalyzed polymerization of cyclic ethers and/or acetals with ring cleavage in the presence of proton donors by a process in which the amount of the relevant proton donor present in the reaction system is regulated in the course of the reaction by the measurement of the electrical conductivity.
摘要:
A process for the preparation of polyether glycols by polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with oxiranes in the presence of from 20 to 500% w/w of a hydrocarbon, based on the weight of tetrahydrofuran used.
摘要:
A process is described for the purification of crude polyalkylene ether glycols contaminated by heteropolyacids or salts thereof, by treatment with solvents, which comprises mixing the crude polyalkylene ether glycols with a liquid hydrocarbon and water, allowing the phases to separate, and isolating the purified polyalkylene ether glycols from the upper phase.
摘要:
2-Methyl-1,4-butanediol and 3-methyltetrahydrofuran are prepared by reacting a compound of the general formula I or II ##STR1## where R.sup.1 and R.sup.2 are each hydrogen or C.sub.1 -C.sub.8 -alkyl and the formyl group of II may also be present as acetal with a C.sub.1 -C.sub.8 -alkanol, is reacted with hydrogen in the presence of copper or of a metal of groups 7 to 10 of the Periodical Table of elements or of a compound of these metals.
摘要:
Mixtures which contain 1,4-butanediol and tetrahydrofuran are prepared by heating 4-hydroxybutyraldehyde of the formula ##STR1## at 20.degree.-300.degree. C. in the presence or absence of 1,4-butanediol and subjecting the resulting acetals of the formulae ##STR2## to a catalytic hydrogenation at 50.degree.-300.degree. C. and 1-350 bar.
摘要:
A process for the preparation of N-substituted lactams of the formula I ##STR1## where Z is C.sub.2 - to C.sub.10 -alkylene, C.sub.7 - to C.sub.12 -aralkylene, phenylene or naphthylene, andR.sup.1 is C.sub.1 - to C.sub.20 -alkyl, C.sub.6 - to C.sub.10 -aryl or C.sub.7 - to C.sub.12 -aralkyl,by hydrogenating a compound of the formula II ##STR2## where W is C.sub.2 - to C.sub.10 -alkylene, C.sub.2 - to C.sub.10 -alkenylene, C.sub.7 - to C.sub.12 -aralkylene, phenylene or naphthylene, andX and Y together form an oxa or imido bridge of the formula ##STR3## or alternatively are identical or different and are hydroxyl, C.sub.1 - to C.sub.20 -alkoxy, C.sub.6 - to C.sub.10 -aryloxy or C.sub.7 - to C.sub.12 -aralkoxy, and, if X and Y are different, Y, in addition to the abovementioned meanings, may also be hydrogen,at superatmospheric pressure and at elevated temperature in the presence of a catalyst and in the presence of an amine, which comprises using a secondary and/or tertiary amine of the formula IIINH.sub.n R.sub.3-n .sup.1where R.sup.1 is as defined above and n is 0 or 1, or a mixture of a secondary and/or teritary amine of this type with a primary amine of the formula IVR.sup.1 --NH.sub.2 (IV)as the starting material, and carrying out the reaction with addition of water and/or ammonia.