Simple method of estimating macroporosity of methyl methacrylate–ethyleneglycol dimethacrylate copolymers

Abstract

Methyl methacrylate–ethyleneglycol dimethacrylate copolymer beads of approximately 300 μm in diameter were synthesized by a suspension polymerization technique. The beads were made porous by dilution of the monomers with some inert organic liquids. The porosity was varied by changing the diluents, by varying the ratios of good solvent to non-solvent component when a mixture of the two was employed as diluent, by varying degree of dilution, and the cross-linkage. Pore volumes, surface areas, and pore size distributions were determined by a mercury penetration method, and densities of the dried copolymers were determined by a measuring cylinder and a balance. Statistical analysis of the data shows that the surface area and swelling coefficient in acetone can be estimated from the pore volume with reasonably good accuracy. Pore size distribution curves for the copolymers having pore volume in the range of 0.06–0.72 ml/g are shown. One can approximately estimate the pore size distribution if the pore volume is known. The pore volume can be estimated with reasonable accuracy from the density of the copolymer.