摘要:
A process for a continuous production of a polyetherol first involves reacting a catalyst (5) with an alcohol starter (3) or an alkoxylated precursor, to give a mixture comprising an alcoholate and water. Water is then removed from the mixture. The process further involves feeding the alcoholate into a bubble column and feeding an alkylene oxide into the bottom of a compartment of the bubble column, such that the alkylene oxide rises in the alcoholate. The alkylene oxide then reacts with the alcoholate or a secondary product from the reaction between the alcoholate and alkylene oxide, to give the polyetherol.
摘要:
A process for a continuous production of a polyetherol first involves reacting an alcohol with a starter or an alkoxylated precursor, to give a mixture comprising an alcoholate and water. Water is then removed from the mixture. The process further involves feeding the alcoholate into a bubble column and feeding an alkylene oxide into the bottom of a compartment of the bubble column, such that the alkylene oxide rises in the alcoholate. The alkylene oxide then reacts with the alcoholate or a secondary product from the reaction between the alcoholate and alkylene oxide, to give the polyetherol.
摘要:
A process for the preparation of polyetherols, comprising the following steps: a) reaction of at least one starter compound with at least one alkylene oxide and a catalyst to give a crude polyetherol and b) removal of low molecular weight byproducts from the crude polyetherol from step a), wherein the crude polyetherol is treated with a stripping gas in a column having internals.
摘要:
The invention provides a process for continuously preparing polyether alcohols using DMC catalysts, which comprises, in a first step, in a continuous reactor, adding alkylene oxides onto H-functional starter substances and transferring the output of this reactor to a second step in a reactor which is divided by closed trays into mutually separate sections, known as compartments, which are connected to one another by external pipelines, in which the output of the reactor from the first step of the reaction passes through the compartments in succession.
摘要:
The invention provides a process for continuously preparing polyether alcohols using DMC catalysts, which comprises, in a first step, in a continuous reactor, adding alkylene oxides onto H-functional starter substances and transferring the output of this reactor to a second step in a reactor which is divided by closed trays into mutually separate sections, known as compartments, which are connected to one another by external pipelines, in which the output of the reactor from the first step of the reaction passes through the compartments in succession.
摘要:
The invention relates to a process for the continuous preparation of polyether alcohols by reacting H-functional initiators with alkylene oxides using basic catalysts, wherein at least one initiator is metered with at least one alkylene oxide continuously into a back-mixing reactor and the reaction product is removed continuously from the back-mixing reactor.
摘要:
A thermoplastic copolymer prepared from acrylonitrile and para-alpha-dimethylstyrene via bulk or solution polymerization has an improved heat distortion temperature and can be used together with graft copolymers and further components for the preparation of thermoplastic moldings.
摘要:
A thermoplastic copolymer prepared from acrylonitrile and para-alpha-dimethylstyrene via bulk or solution polymerization has an improved heat distortion temperature and can be used together with graft copolymers and further components for the preparation of thermoplastic moldings.
摘要:
The invention provides a process for preparing polyether alcohols by adding alkylene oxides onto H-functional starter substances, of which at least one is solid at room temperature in a reaction vessel, by feeding the starting components continuously to the reaction vessel, which comprises preparing a paste from the solid starter substance and feeding this paste continuously to the reaction vessel.
摘要:
The present invention relates to processes for preparing copolymers A) with a reduced soil particle content, comprising 49.2 to 93.2% by weight of structural units which derive from one or more vinylaromatic monomers (component A1)), 6 to 50% by weight of structural units which derive from one or more vinyl cyanides (component A2)), 0.8 to 7% by weight of structural units which derive from one or more dicarboxylic anhydrides (component A3)) and 0 to 25% by weight of structural units which derive from further copolymerizable monomers (component A4)), where the percentages by weight are each based on the total weight of the structural units which derive from components A1), A2), A3) and A4), and together add up to 100% by weight, by bulk or solution polymerization, it being essential to the invention that the mathematical product of the percentages by weight of the structural units which derive from component A2) and the percentages by weight of the structural units which derive from component A3) in the copolymer A) is in the range from 40%2 by weight to 65%2 by weight. The present invention further relates to the copolymers A), to thermoplastic molding materials comprising the copolymers A), to the use of the copolymers A) and of the thermoplastic molding materials, and to the moldings, films, fibers and foams obtainable from the copolymers A) and the thermoplastic molding materials.