摘要:
The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.
摘要:
The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.
摘要:
The invention relates to a process for the pretreatment of material surfaces in order to minimize the interaction between polycarbonate and metal and, in the processing and synthesis of polycarbonate, to obtain a high-quality polymer which in particular does not become discolored and is free of insoluble constituents.
摘要:
The invention relates to a process for the pretreatment of material surfaces in order to minimize the interaction between polycarbonate and metal and, in the processing and synthesis of polycarbonate, to obtain a high-quality polymer which in particular does not become discoloured and is free of insoluble constituents.
摘要:
The present invention relates to a process for working up solutions of polymers in organic solvents contaminated by alkaline constituents, using homogeneously soluble acids, especially by the introduction of an acid gas, and subsequent washing, and to the polymers so obtainable, which are distinguished by the fact that, on treatment with moist heat (sterilisation), only few defects caused by decomposition are formed, to the use thereof in the production of extrudates and molded specimen, and to the extrudates and molded specimen produced from those polymers themselves.