Poly(2-acrylamido-2-methylpropanesulphonic acid) and polymer complexes of 2-acrylamido-2-methylpropanesulphonic acid with nickel(II), copper(I1) ,iron(III) chlorides and cobalt (11) sulphate, respectively, were prepared and characterized by spectroscopic techniques. Thermal stability of the formed polymer complexes was determined by means of thermogravimetric analysis. It was found that the thermal stability of the homopolymer is less than that of the polymer complexes. The activation energies of the degradation of the polymer complexes were determined by using the Arrhenius equation. Die thermische Stabilitat von Poly(2-ac1ylamido-2-methylpropansulfonsaure) und der polymeren Komplexe von 2-Acrylamido-2-methylpropansulfonsaure rnit einigen Salzen von UbergangsmetallenPoly(2-acrylamido-2-methylpropansulfonsaure) sowie polymere Komplexe von 2-Acrylamido-2-methylpropansulfonsaure mit Nickel(I1)-, Kupfer(I1)-, Eisen(II1)-chlorid und Kobalt(I1)sulfat wurden hergestellt und rnit spektroskopischen Methoden charakterisiert. Die thermische Stabilitat der gebildeten Polymerkomplexe wurde mittels thermogravimetrischer Analyse bestimmt. Es wurde festgestellt, daI3 die thermische Stabilitat des Homopolymers geringer ist als die der Polymerkomplexe. Die Aktivierungsenergy des Abbaus der Polymerkomplexe wurde mit der Arrhenius-Gleichung ermittelt.

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Hydrogels with moderate water retention capacity and salt stability have been prepared from starch, oxidized starch, and amylopectin all crosslinked with epichlorohydrin. The swelling power was measured in water and in various salt solutions of different concentrations. The swelling capacity decreases with increasing both the crosslinker and the polymer concentration. The plateau modulus (G′p) of the prepared gels was determined from complex dynamic viscosity measurements. G′p was measured as a function of the epichlorohydrin and polymer concentrations. The loss modulus (G″) for the prepared gels was also measured and was always found to be almost zero. The molecular weight between two entanglement points (mesh width) was estimated from the G′p values. The ratio between the number of elastically effective entanglement points, calculated from the G′p values, and that calculated from complete conversion of the cross‐linker was also estimated for various gels. It was found that this ratio is very small (0.2–0.7%) for gels prepared with 10 wt‐% starch, it increases however to 13% at higher starch concentration of 25 wt‐%.

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