Abstract:
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.
Abstract:
The invention concerns tetrahydrofuran/but-2-ine-1,4-diol copolymers containing C-C triple bonds, the copolymers having a mean molecular weight Mn of 500 to 3,500 Daltons and containing 0.5 to 3 moles of triple bonds per mole of copolymer, as well as blends of these copolymers with polytetrahydrofuran having a mean molecular weight Mn of 500 to 3,500 Daltons. The invention also concerns a method of producing such copolymers or blends and their use.
Abstract:
The invention relates to thermoplastic polyurethane elastomers obtainable by inaction of a) unmodified and/or modified organic polyisocyanates, preferably 4,4'diisocyanatodiphenylmethane, with b) polyoxybutylene glycols and/or polyoxybutylene/polyoxyalkylene glycols with a molecular weight of from 150 to 1800 and a content of crown ethers, preferably those of the formula (-CH2CH2CH2CH2O-)m, where m is from 3 to 6, not exceeding 0.06% of the total weight and c) chain extenders with a molecular weight of from 60 to 400, preferably 1,4-butanediol, to a process for the preparation thereof and to the use thereof for producing molded articles and sheets for use in the medical or hygiene sector and in the foodstuffs sector.
Abstract:
A process for the continuous production of tetrahydrofuran (THF) by reaction of a 1,4-butanediol reaction mixture at a heteropolyacid catalyst that has not been pre-dried is characterized in that the reaction mixture contains 2-(4-hydroxybutoxy)tetrahydrofuran.
Abstract:
A process for the continuous production of tetrahydrofuran (THF) by reaction of a 1,4-butanediol reaction mixture at a heteropolyacid catalyst that has not been pre-dried is characterized in that the reaction mixture contains 2-(4-hydroxybutoxy)tetrahydrofuran.
Abstract:
A process for the continuous production of tetrahydrofuran (THF) by reaction of a 1,4-butanediol reaction mixture at a heteropolyacid catalyst that has not been pre-dried is characterized in that the reaction mixture contains 2-(4-hydroxybutoxy)tetrahydrofuran.
Abstract:
The invention relates to a method for purifying a polyalcohol of general formula (I) wherein R can be the same or different and can represent a substituted or unsubstituted aliphatic hydrocarbon having 1 - 22 C atoms, an aryl or an arylalkyl group having 6 - 22 C atoms or a methylol group. By treating the polyalcohols of general formula (I) with at least one acid and/or basic ion exchanger, the CPR value can be adjusted from 0 to +1.5.
Abstract:
PCT No. PCT/EP96/00702 Sec. 371 Date Aug. 26, 1997 Sec. 102(e) Date Aug. 26, 1997 PCT Filed Feb. 21, 1996 PCT Pub. No. WO96/27626 PCT Pub. Date Sep. 12, 1996Tetrahydrofuran/but-2-yne-1,4-diol copolymers containing C-C triple bonds and having an average molecular weight Mn of from 500 to 3500 Dalton and a content of from 0.5 to 3 mol of triple bonds/mol of copolymer and blends of these copolymers with polytetrahydrofuran having an average molecular weight Mn of from 500 to 3500 Dalton, processes for their preparation and their use.
Abstract:
Procedimiento para la obtención en continuo de THF mediante reacción de una mezcla de reacción, que contiene 1, 4-butanodiol, sobre un catalizador de heteropoliácidos no secado previamente, caracterizado porque la mezcla de la reacción contiene por debajo de 1 ppm de componentes nitrogenados básicos y de 2-(4-hidroxibutoxi)-tetrahidrofurano.
Abstract:
A process for the continuous production of tetrahydrofuran (THF) by reaction of a 1,4-butanediol reaction mixture at a heteropolyacid catalyst that has not been pre-dried is characterized in that the reaction mixture contains 2-(4-hydroxybutoxy)tetrahydrofuran.