Beschreibung:
<jats:title>Abstract</jats:title><jats:p>The mechanical properties and the swelling behaviour of aqueous poly(acryl amide) and poly(acryl amide‐co‐Na acrylate) gels were investigated. The ionic networks were prepared by hydrolysis of the nonionic ones, in this way preserving the network topology. By measurement of the modulus it was detected that networks prepared in solution contain a rather large portion of elastically ineffective rings. Hydrolysing a part of the amide groups resulted in a considerably increased swelling ratio. The modulus of such ionic gels did not show the predicted decrease with rising swelling ratio, but on the contrary increased up to a fivefold value. The reason for this behaviour is seen in the limited extensibility (non‐Gaussian behaviour) of the network chains. At constant swelling ratio, the modulus of gels having identical topology decreased with rising degree of hydrolysis. This reflects the influence of the ionic groups on the mean‐square end‐to‐end distance of the free polymer chains.</jats:p>