Abstract: The present invention provides a method for purifying laurolactam from a crude lactam mixture. In the method of the present invention, laurolactam is selectively crystallized by melt crystallization with controlled cooling of the crude lactam mixture.

Abstract: A process for preparing a polyarylene ether ketone, comprising: a) reacting an aromatic dihalogen compound with a bisphenol and/or a halophenol in the presence of alkali metal carbonate and/or alkaline earth metal carbonate in a high-boiling aprotic solvent to give a polyarylene ether ketone, b) wet-comminuting the solidified reaction mixture in the presence of water, c) washing with an organic solvent, d) washing with water and e) drying the washed product, wherein the wet-comminuted reaction mixture is fed to the two-stage washing with a residual moisture content of at least 1% by weight, which process leads to distinctly reduced residual contents of salts and reaction solvents.

Abstract: A process for preparing a polyarylene ether ketone comprises the following process steps: a) reaction of an aromatic dihalogen compound with a bisphenol and/or a halophenol in the presence of alkali metal and/or alkaline earth metal carbonate or hydrogencarbonate in a high-boiling aprotic solvent to give a polyarylene ether ketone, b) wet comminution and simultaneous preextraction of the solidified reaction mixture, c) extraction and filtration of the wet-comminuted product in a pressure suction filter and d) drying of the extracted product. This combination enables improved workup of the reaction mixture.

Abstract: A process for preparing a polyarylene ether ketone by reacting an aromatic dihalogen compound with a bisphenol in the presence of alkali metal carbonate and/or alkaline earth metal carbonate in a high-boiling solvent, where the molar mass is established by, in the course of the polycondensation, bringing the molar mass to a target value by again adding a bisphenol or an aromatic dihalogen compound to the reaction.

Abstract: A process for preparing a polyarylene ether ketone, comprising: a) reacting an aromatic dihalogen compound with a bisphenol and/or a halophenol in the presence of alkali metal carbonate and/or alkaline earth metal carbonate in a high-boiling aprotic solvent to give a polyarylene ether ketone, b) wet-comminuting the solidified reaction mixture in the presence of water, c) washing with an organic solvent, d) washing with water and e) drying the washed product, wherein the wet-comminuted reaction mixture is fed to the two-stage washing with a residual moisture content of at least 1% by weight, which process leads to distinctly reduced residual contents of salts and reaction solvents.

Abstract: The epoxidation of cyclic, at least monounsaturated alkenes is conducted by a process, which comprises conducting the epoxidation of a cyclic, at least monounsaturated alkene in the presence of an oxidant in a reaction medium that contains at least 1% by weight of the saturated cyclic alkane corresponding to the cyclic, at least monounsaturated alkene. In a preferred embodiment the reaction medium contains at least 2.5% by weight of the saturated cyclic alkane corresponding to the cyclic, at least monounsaturated alkene.

Abstract: The epoxidation of cyclic, at least monounsaturated alkenes is conducted by a process, which comprises conducting the epoxidation of a cyclic, at least monounsaturated alkene in the presence of an oxidant in a reaction medium that contains at least 1% by weight of the saturated cyclic alkane corresponding to the cyclic, at least monounsaturated alkene. In a preferred embodiment the reaction medium contains at least 2.5% by weight of the saturated cyclic alkane corresponding to the cyclic, at least monounsaturated alkene.