摘要:
Preparation of cyclododecatriene in a continuous or discontinuous process by trimerization of butadiene in the presence of a catalyst system and a solvent, the crude cyclododecatriene obtained being able to be isolated by means of distillation. The cyclooctadiene formed as by-product can likewise be isolated from the crude product.
摘要:
A polyoctenamer is described which at room temperature is liquid, colourless and clear, and which is produced by ring-opening, metathesis polymerization of cyclooctene.
摘要:
A process for preparing cyclododecene by selective gas-phase hydrogenation of at least one starting material selected from cyclododecatriene, cyclododecadiene and mixtures thereof, wherein the starting material present in the gas phase is hydrogenated in the presence of a catalyst in a fixed-bed reactor and the Bodenstein number for the process is greater than 100.
摘要:
Preparation of cyclododecatriene in a continuous or discontinuous process by trimerization of butadiene in the presence of a catalyst system and a solvent, the crude cyclododecatriene obtained being able to be isolated by means of distillation. The cyclooctadiene formed as by-product can likewise be isolated from the crude product.
摘要:
The invention relates to a method for the purification of poly(arylene ethers) of formula (I) in which m=0 to 1.0, n=1.0-m, and Ar1, Ar2, Ar3 and Ar4 independently represent divalent arylene groups. The compound of formula (I) is produced in a first step 1, with a raw product being obtained by bringing a metal or ammonium salt of divalent dihydroxy derivatives of Ar1 or Ar3 into contact with one or more dihalogenated derivatives of Ar2 and/or Ar4, in the presence of a solvent LM1. A precipitate that is present, if appropriate, is separated (step B) so as to obtain a solution L which then undergoes a membrane filtration (step C).
摘要:
The invention relates to a method for the purification of poly(arylene ethers) of formula (I) in which m=0 to 1.0, n=1.0-m, and Ar1, Ar2, Ar3 and Ar4 independently represent divalent arylene groups. The compound of formula (I) is produced in a first step 1, with a raw product being obtained by bringing a metal or ammonium salt of divalent dihydroxy derivatives of Ar1 or Ar3 into contact with one or more dihalogenated derivatives of Ar2 and/or Ar4, in the presence of a solvent LM1. A precipitate that is present, if appropriate, is separated (step B) so as to obtain a solution L which then undergoes a membrane filtration (step C).
摘要:
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.
摘要:
Cyclododecanone (CDON) is prepared by epoxidizing cyclododecene (CDEN) to epoxycyclododecane (CDAN epoxide), and rearranging the CDAN epoxide to CDON to obtain a mixture comprising said CDON and CDEN, wherein CDEN is separated from the CDON-containing mixture and sent to the epoxidation to CDAN epoxide in step a.
摘要:
A process for purifying laurolactam by means of integrated connection of distillation and crystallization is provided. The crystallization is performed as a solution or melt crystallization. The process reduces thermal stress applied to the laurolactam stream and improved yields are obtained. Raw materials are recovered and recycled in the production sequence.
摘要:
A process for preparing an alpha, omega-dicarboxylic acid or an ester thereof, which includes (a) subjecting at least one unsaturated fatty acid or fatty acid derivative to ozonolysis to obtain an ozonolysis reaction mixture; and (b) oxidizing the ozonolysis reaction mixture with an oxidizing agent in the presence of an acid catalyst to obtain an oxidized reaction mixture comprising at least one alpha, omega-dicarboxylic acid or ester; wherein the process is performed using a solvent and the acid catalyst has a pKa of less than or equal to zero, as measured at 25° C.