Suspensions of poly(acrylic acid) particles with an average diameter of about 90 nm in benzene were prepared by dispersion polymerization. Using dioyl dichloride or diglycidyl ether as crosslinking agent the poly(acrylic acid) particles can be linked with each other, and a gel with three-dimensional network structure was formed. After removal of the solvent from the gel by freeze-drying a porous polymeric material can be obtained. Depending on the concentration of crosslinking agent and the polymer content of the suspension a porous material of poly(acrylic acid) with porosity as high as 0.95 and density as low as 0.07 g cm(-3) is achieved. The process of gelation was studied by dynamic rheology, light scattering and calorimetric measurements.