The thermal stability of the perfluorinated cationexchange membrane Nation-417 was determined by means of simultaneous TG-DTA. The individual decomposition stages were studied via IR spectroscopy and ion-exchange capacity determinations. Nafion-417 is thermally stable up to 280 ~ Above this temperature, sulfonic groups present in the membrane are split off (Tmax ----345 ~ In the temperature range 420-590 ~ oxidative destruction of the perfluorinated matrix occurs, which is accompanied by practically total weight loss.Perfluorinated ionomer membranes represent a major advance in membrane technology. Although a variety of applications have been found for these polymers since their appearance about fifteen years ago, the main driving force for their development has been their potential application as membrane separators in commercial alkali metal chloride solution electrolysis. This major chemical technology is in the process of being revolutionized through the use of these materials.Among the polymeric synthetic ion-exchange membranes, special attention has been paid to the Nation membranes, based on sulfonated fluorocarbons. Owing to their chemical inertness, thermal and mechanical stability, and high permeability and mechanical stability, and high permeability and selectivity, they have proved to be particularly suitable for many industrial processes [1,2]. Nation membranes have found wide application in the chemical industry, e.g. as separators in chloralkali electrolysis or as solid polymer electrolytes in fuel cells [3]. Perfluorinated ion-exchange polymers can also serve as "superacid" catalysts for many organic reactions [4].The structures and physicochemical.properties of Nation membranes have been studied extensively by many authors [1,[5][6][7][8][9]. Only a few papers have been published on the thermal stabilities of Nation membranes; these have concerned the thermal behaviour of Nafion in solutions of chemicals up to 200-250 ~ .The purpose of our studies was to investigate the thermal properties of Nafion-417 in the temperature range 20-1000 ~ through the use of thermogravimetry (TG) and differential thermal analysis (DTA).

Starting from a commercial sulphonate cation-exchange resin via sulphonyl chloride and sulphonamide resins, a macromolecular dichloroamine with ca. 6 mmol of active chlorine per gram of resin was prepared. The conditions for its optimum preparation starting from poly(styrene-co-diviny1benzene)sulphonamide (poly(St-Co-DVB)SQNH,) were stated. The possibility of iterated chlorination and dechlorination of the product was proved. Its stability in the range of 20-100"C, both in the dry state and in aqueous media, was determined. Moreover, its derivatographic examinations up to 1OOO"C were performed. Examples for the use of the macromolecular dichloroamine as a polymer supported reagent for chlorination, oxidation of several organic and inorganic species and water disinfection are given. ZUS AMMENFASSUNG:Ausgehend von einem handelsublichen makropor6sen Sulfonat-Kationenaustauscher wurde Uber Sulfonylchlorid-und Sulfonamid-Harze ein hochmolekulares Dichloramin mit fast 6 mmol aktivem Chlor pro Gramm des Harzes hergestellt. Die besten Bedingungen fur den hochsten Umsatz von Poly(styro1-co-divinylbenzol) sulfonamid (Poly(St-Co-DVB)SQNH,) zum Dichloramin wurden ermittelt. Es wurde festgestellt, da8 die wiederholte Dechlorierung und Chlorierung der Produkte ohne merklichen Abbau abliiuft. Es wurde die Bestiindigkeit im Temperaturbereich von 20-100°C gemessen und zwar sowohl im trockenen Zustand als auch in wiifirigen Medien. Dartiber hinaus wurden derivatographische Messungen bis 1 OOO "C durchgefiihrt. Es werden auch Beispiele fur die Anwendung des Dichloramins als polymeres Reagenz fur Chlorierungen, Oxidationen von organischen und anorganischen Verbindungen und fur die Wasserdesinfektion gegeben.

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Macromolecular pendant group N-monobromosulphonamide metal salts @-S0,NBr -M + having a macroporous styrene-divinylbenzene matrix structure have been obtained by two methods: a) by the action of aqueous metal hypobromites on the appropriate macromolecular pendant group sulphonamide, and b) by the action of an aqueous metal bromide on the appropriate macromolecular N-chlorosulphonamide metal salt.In each case the sodium salt product was obtained with a 100% functional yield and it contained 2.1 mmol-g-' -SO,NBr-Na+ groups, i.e., 4.2 meqeg-' of active bromine. The stability of the resin was investigated in the range 20-100 "C in the dry state as well as in aqueous media.A thermoanalysis (TG, DTG, and DTA curves) was carried out up to lo00 "C and its course was interpreted. The resin has brominating, oxidative, microbiocidic, and ionexchanging properties. It reacts in a reversible way: after the loss of the active bromine, it can be reactivated again. ZUSAMMENFASSUNG:Zwei Methoden zur Herstellung hochmolekularer poroser "Bromamine" ( @-S0,NBr -Na+) mit Poly (styrol-co-divinylbenzo1)-Matrix wurden untersucht, und zwar a) die Einwirkung von Hypobromiten auf das die entsprechenden Sulfonamidseitengruppen enthaltende Copolymere, und b) die Einwirkung von Bromiden auf das entsprechende hochmolekulare "Chloramin". In beiden Fallen wurden Metallsalze des hochmolekularen "Bromamins" erhalten. Das Natriumsalz wurde mit einer 100-proz. Ausbeute an funktionellen Gruppen erhalten; es enthielt 2.1 mmol. g-' -SO,NBr-Na+ Gruppen, d. h. 4.2 meq . g-' aktives Brom. Es wurde auch die Stabilitat des Harzes getestet, und zwar im Bereich von 20-100 "C sowohl im trockenen Zustand als auch in wti8rigen Medien. Daruber hinaus wurden thermoanalytische Messungen bis 1OOO"C durchgefuhrt. Es wurden auch Beispiele fur die Anwendung des 0 1991 Huthig & Wepf Verlag, Base1 CCC OOO3-3146/91/$03.00 85 R. Bogoczek and E. Kociolek-Balawejder "Bromamins" als polymeres Reagenz fur Bromierungen (Iodierungen), Oxidationen, Wasserdesinfektion und Kationenaustausch gegeben. Dieses sehr reaktive polymere Reagenz kann ohne merklichen Verlust seiner Eigenschaften wiederholt debromiert und bromiert werden.