PREPARATION OF POLYMERIC POROUS MATERIALS BY INTERPARTICLE CROSS-LINKING

Suspensions of poly(acrylic acid) particles with an average diameter o f about 90 nm in benzene were prepared by dispersion polymerization. U sing dioyl dichloride or diglycidyl ether as crosslinking agent the po ly(acrylic acid) particles can be linked with each other, and a gel wi th three-dimensional network structure was formed. After removal of th e solvent from the gel by freeze-drying a porous polymeric material ca n be obtained. Depending on the concentration of crosslinking agent an d the polymer content of the suspension a porous material of poly(acry lic acid) with porosity as high as 0.95 and density as low as 0.07 g c m(-3) is achieved. The process of gelation was studied by dynamic rheo logy, light scattering and calorimetric measurements. Copyright (C) 19 96 Elsevier Science Ltd.