Synthetic crosslinked polymers were obtained by reacting oligomers of polybutadiene (av. mel. wt. similar to 6000) with acrylamide and acrylic acid. Characterization of these new block-crosslinked polymers was carried out by FTIR, H-1-NMR, C-13-NMR, SEM analyses, DTA, and DTG. The polymers were washed with benzene, ethanol, water, and acetone and then dried at high vacuum. Determinations of the swelling ratio Vs/Vo for the poly (BuAAAm)H, acid form, and poly (BuAAAm)Na, sodium form, were carried out in distilled water, at different pH values and concentrations of electrolytes. Kinetic studies with diffusion of solvents were related to the network structures of the poly (BuAAAm) in acid and sodium forms.