Vous avez des questions?Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Functional group polysulphones by bromination-metalation Guiver, Michael D.; Kutowy, O.; ApSimon, John W. https://publications-cnrc.canada.ca/fra/droits L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le siteA variety of functional groups can be substituted on aromatic polysulphones by a process of bromination followed by metalation. Both Udel polysulphone and Radel polyphenylsulphone were brominated at room temperature using bromine without a catalyst. Repeat units containing two bromine atoms at the electrophilic site in the bisphenol portion were obtained when excess reagent was used. These polymers readily undergo metal-halogen exchange with n-butyllithium. The resulting polyanionic lithiated polysulphones are reactive to a variety of electrophiles and give polymers containing functional groups such as carboxyl and hydroxyl. These polymers are useful as membrane materials.
Polysulfone has been carboxylated, via a metalated intermediate, by reaction of a THF solution of polymer with n‐butyllithium and then treatment with carbon dioxide. The polymer reactions with n‐butyllithium were close to quantitative and did not require the use of a tertiary amine catalyst. A series of polymers ranging from 0.2 to 1.9 carboxyl groups per repeat unit was prepared by this method in the salt, acid and ester form. The structures of these polymer derivatives were characterized by 1H‐NMR, 13C‐NMR and IR. The glass transition temperatures and thermal stabilities were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG).
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à
SynopsisTwenty-three different casting solution compositions involving cellulose acetate (E-938-3 (polymer, P), acetone (solvent, S), and aqueous magnesium perchlorate (Mg(ClO&: HzO = 1 : 8.5) (nonsolvent, N) were studied for making ultrafiltration membranes. These compositions (expressed in weight units) involved N / P ratios of 0.817 to 1.3 and S/P ratios of 3.5 to 5.33. I t WBS found that by adjusting the values of S/P and N/P ratios in the casting solution composition, temperature of the casting solution, temperature of the casting atmosphere, and solvent evaporation period during film formation, a wide variety of cellulose acetate membranes useful for both ultrafiltration and reverse osmosis applications could be obtained. The results of a continuous test run a t 50 psig for a period of 250 hr with a typical set of membranes, and their separation characteristics for a group of solutes ranging in molecular weight from 58 to 16o,OOO, are presented.
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