Abstract: A method of using Raman Spectra for determining the progress of a graft polymerization reaction is disclosed. The method entails (a) measuring at the beginning of the reaction and at a plurality of time intervals in the course of the reaction, continuously and on-site, the Raman spectrum in the wave number range of 100 to 4000 cm?1 of one or more of the monomers and/or polymers entailed in the reaction and of at least one internal standard and (b) recording the spectra and (c) adding reaction partners necessary to the reaction continuously and/or discontinuously and (d) calculating the change in concentration of the monomers and polymers by comparing the spectra of the monomers or polymers with the internal standard.

Abstract: A process of producing a graft polymer of the ABS type by the emulsion method is disclosed. In the process wherein 5 to 95% by weight of a monomer mixture that contains A) 50 to 99 parts by weight of at least one vinyl aromatic compound and B) 1 to 50 parts by weight of at least one copolymer is polymerized in the presence of C) 95 to 5% by weight of one or more graft substrates having a glass transition temperature <10° C., the improvement includes monitoring continuously in the course of the reaction the Raman spectra of the reaction mixture, determining deviations from the specified desired course of the reaction and making corresponding adjustments.

Abstract: The present invention relates to a process for preparing crosslinked ion exchangers with a homogeneous network structure based on unsaturated aliphatic nitriles in the presence of film-forming protective colloids.

Abstract: A process of preparing a graft polymer (e.g., an ABS graft copolymer), which involves determining the concentration of at least one reaction component during the course of the reaction by means of Raman spectroscopy, is disclosed. The process, more particularly, comprises: (a) synthesizing the graft polymer from a reaction mixture comprising reactive components (e.g., monomers such as styrene and acrylonitrile, and a graft base); (b) analyzing the reaction mixture, at intervals, during the synthesis of the graft polymer, by means of Raman spectra; (c) recording the results of the Raman spectra analysis; (d) determining the concentration of at least one of said reactive components (e.g., styrene) by means of spectral evaluation of the recorded Raman spectra; and (e) terminating the synthesis reaction of the graft polymer when the concentration of at least one of the reactive components has reached a predetermined concentration value.

Abstract: A method of using Raman Spectra for determining the progress of a graft polymerization reaction is disclosed. The method entails (a) measuring at the beginning of the reaction and at a plurality of time intervals in the course of the reaction, continuously and on-site, the Raman spectrum in the wave number range of 100 to 4000 cm−1 of one or more of the monomers and/or polymers entailed in the reaction and of at least one internal standard and (b) recording the spectra and (c) adding reaction partners necessary to the reaction continuously and/or discontinuously and (d) calculating the change in concentration of the monomers and polymers by comparing the spectra of the monomers or polymers with the internal standard.

Abstract: The invention relates to a process for preparing gel-type cation exchangers of high osmotic and mechanical stability and enhanced stability to oxidation by a seed/feed process, the seed used being a polymer containing 3.5-7% by weight of crosslinker.

Abstract: The present invention relates to a process for polymerizing a mixture of one or more monovinyl monomers and one or more polyvinyl monomers in the presence of

Abstract: The invention relates to a process for preparing monodisperse cation-exchanger gels with increased oxidation resistance and with high osmotic stability and purity by

Abstract: The present invention relates to a process for preparing crosslinked ion exchangers with a homogeneous network structure based on unsaturated aliphatic nitrites in the presence of film-forming protective colloids.