摘要:
The present invention relates to a process for preparing sulfur-containing polymers from at least one sulfide and at least one aromatic dihalo compound in a solvent, which comprisesa) reacting the sulfide with a stoichiometric excess of aromatic dihalo compound,b) largely removing the excess aromatic dihalo compound andc) further polymerizing the mixture.
摘要:
The present invention relates to a process and an apparatus for separating separating polymeric from one or more by-products of preparation of the polymer and a first liquid phase, wherein the solid in a first liquid phase is brought into contact with a second liquid phase and the solid is transferred into the second liquid phase. The solid is washed in countercurrent and at least partial displacement washing takes place during the washing of the solid.
摘要:
Processes are described which comprise: (a) providing a mixture comprising a cyclic formal and water, wherein the mixture has a cyclic formal concentration and a water concentration; (b) bringing the mixture into contact with an aqueously selective membrane; (c) creating a pressure differential across the membrane; and (d) obtaining a permeate having a higher water concentration and a lower cyclic formal concentration than the mixture, and a retentate having a lower water concentration and a higher cyclic formal concentration than the mixture.
摘要:
In a process for preparing aromatic sulfur-containing polymers, the polymer is formed from a prepolymer having halogen end groups. During preparation of the prepolymers, an alkali equivalent and a sulfur equivalent in a ratio of 0.5 to 1:1 is employed in the reaction mixture. The two-step process is particularly suitable for preparing polyphenylene sulfide.
摘要:
Processes are described which comprise: (a) providing a mixture comprising a cyclic formal and water, wherein the mixture has a cyclic formal concentration and a water concentration; (b) bringing the mixture into contact with an organically selective membrane; (c) creating a pressure differential across the membrane; and (d) obtaining a permeate having a lower water concentration and a higher cyclic formal concentration than the mixture, and a retentate having a higher water concentration and a lower cyclic formal concentration than the mixture.
摘要:
The process for preparing sulfur-containing polymers, in particular polyarylene sulfides, from at least one sulfide and at least one aromatic dihalogen compound, in a solvent, is carried out in the steps: a) a mixture of aromatic dihalogen compound and sulfide is polymerized, b) aromatic dihalogen compound and sulfide are added to the polymerized mixture and c) the reaction mixture is polymerized further. The sulfur-containing polymers prepared by the process are distinguished by high purity and good mechanical properties.
摘要:
The invention relates to a method of material separation, in which a material, which comprises at least a first material component and a second material component, is introduced, together with a washing fluid, into a container with at least one sedimentation chamber and is subjected to a gravitational field, under influence of the gravitational field in the sedimentation chamber, the first material component is enriched in a sedimentation zone, which is bounded by a base, and the material with the enriched first material component is evacuated from the sedimentation zone via an opening in the base, the material with the enriched first material component being evacuated as a sediment film through the opening in the base, washing fluid flowing transversely onto the sediment film and the washing fluid flowing through the sediment film and, in the process, an at least partial displacement of the remaining second material component taking place from the sediment film. The invention further relates to an appliance, in particular for carrying out the method.
摘要:
The present invention relates to a process for separating a dissolved polymer from solids, wherein the solid is separated off by sedimentation and the sedimented solid is washed in countercurrent with a solvent. The present invention further relates to a process for preparing polymers in a solvent, wherein a) a polymer having a low molecular weight is prepared in solution, b) the solid which is undissolved in the reaction mixture is separated off by sedimentation and c) the mixture which has been freed of the solid is polymerized further until a particular molecular weight has been reached.
摘要:
The present invention relates to a process for preparing sulfur-containing polymers from at least one sulfide and from at least one aromatic dihalogen compound in at least one solvent, where a) a mixture made from a sulfide and from a solvent is prepared in a first reaction vessel, b) the sulfide and an aromatic dihalogen compound react in a second reaction vessel to form a sulfur-containing polymer, c) the pressure in the second reaction vessel is to some extent or completely released during the reaction, and the emanating vapor mixture is brought into contact with the mixture prepared in step (a).
摘要:
The present invention relates to a process for the preparation of oxymethylene polymers as well as oxymethylene polymers obtainable therefrom. The process includes polymerization of a monomer, which forms —CH2—O— units in the presence of an acetal of formaldehyde or a polyhydric alcohol and an initiator for cationic polymerization. The initiator may be a heteropoly acid or an acid salt thereof which is dissolved in an alkyl ester of a polybasic carboxylic acid.