摘要:
The invention relates to a method for producing monoesters or diesters of polytetrahydrofuran or of tetrahydrofuran copolymers by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer on an acid catalyst. According to the invention, the polymerization reactor is started up with a mixture consisting of polytetrahydrofuran, the monoesters or diesters of the polytetrahydrofuran and/or of the THF copolymers, tetrahydrofuran, optionally, a comonomer and of at least one carboxylic acid and/or of a carboxylic acid anhydride.
摘要:
The invention relates to a method for the single-stage production of polytetrahydrofuran and/or tetrahydrofuran-copolymers with an average molecular weight of between 650 and 5000 Dalton, by the polymerisation of tetrahydrofuran on an acidic catalyst, in the presence of at least one telogen and/or comonomer. Said method is characterised in that the telogen and/or comonomer is added at a minimum of two dosing points in different sections of the polymerisation apparatus.
摘要:
In a process for finishing neopentyl glycol by cooling, crystallizing and comminuting a neopentyl glycol melt and subsequent packing of the resulting neopentyl glycol particles in storage or transport containers, the melt is cooled at the commencement of cooling for at least 1/10 minutes without use of a coolant or with use of a colant having a temperature in the range from 50 to 120 °C and the product is packed at a temperature below 30 °C.
摘要:
Improved method for the production of η, δ-unsaturated ketones desired as odoriferous substances or as intermediate products for vitamins or carotinoids by the reaction of tertiary allyl alcohols and alkenyl alkyl ethers in the presence of acid catalyzers at high temperature. It is characterized in that the reaction is carried out in the presence of a phosphorus derivative of general formula (IV), in which A and B stand for a branched or unbranched alkyl or alkoxy radical with 1 to 10 C atoms, an optionally substituted aryl radical, cycloalkyl radical, aryloxy radical or cycloalkyloxy radical. In addition, A can stand for -H or -OH, or A and B together stand for an optionally substituted tetramethylene or pentamethylene radical, or for an optionally substituted phenyl-1,2-diol radical or a 1,1'-binaphthyl-2,2'-diol radical.
摘要:
The invention relates to a method for the continuous production of THF by reacting a reaction mixture containing 1.4-butandiol with a non-predried heteropolyacidic catalyst. The invention is characterised in that the reaction mixture contains 2-(4-hydroxybutoxy)-tetrahydrofuran.
摘要:
The invention relates to a method for the continuous production of THF by reacting a reaction mixture containing 1.4-butandiol with a non-predried heteropolyacidic catalyst. The invention is characterised in that the reaction mixture contains 2-(4-hydroxybutoxy)-tetrahydrofuran.
摘要:
The invention relates to a method of producing the N-substituted 2,6-dialkyl morpholines of general formula (I), wherein R?1 and R2¿ independently represent hydrogen, alkyl or cycloalkyl, or R?1 and R2¿, together with the carbon atom to which they are bound, represent a 5 to 14 membered carbocyclic compound, and R?3 and R4¿ independently represent alkyl or cycloalkyl. The inventive substances are produced by reacting at least one carbonyl compound of general formula (II), wherein R?1 and R2¿ are defined as above, with at least one morpholine of general formula (III), wherein R?3 and R4¿ are defined as above, in the presence of hydrogen and at least one metal-containing catalyst, the active component of said catalyst substantially consisting of platinum group metals.
摘要:
The invention relates to a solid, acid catalyst for the production of polytetrahydrofuran, polytetrahydrofuran copolymers, diesters or monoesters of said polymers by the polymerisation of tetrahydrofuran in the presence of at least one telogen and/or comonomer. Said catalyst has a BET surface area of at least 160 m2/g and an acid site density of at least 0.05 mmol/g for pKs values of between 1 and 6. The invention also relates to a method for producing the catalyst and to a method for the polymerisation of cyclic ethers on said catalyst.
摘要:
The invention relates to a method for producing monoesters or diesters of polytetrahydrofuran or of tetrahydrofuran copolymers by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer on an acid catalyst. According to the invention, the polymerization reactor is started up with a mixture consisting of polytetrahydrofuran, the monoesters or diesters of the polytetrahydrofuran and/or of the THF copolymers, tetrahydrofuran, optionally, a comonomer and of at least one carboxylic acid and/or of a carboxylic acid anhydride.