abstract |
A method for increasing the porosity of a cross-linked copolymer composed essentially of at least one monovinyl aromatic compound selected from the group consisting of styrene, vinyl toluene and ethyl vinyl benzene, at least one polyvinyl aromatic compound selected from the group consisting of divinyl benzene, trivinyl benzene, divinyl toluene and divinyl xylene, and an aliphatic vinyl compound, wherein the proportion of the polyvinyl aromatic compound relative to the total vinyl compounds is from 8 to 80% by weight, and the proportion of the aliphatic vinyl compound relative to the total vinyl compounds is from 0 to 20% by weight, which method comprises treating particles of said copolymer with a Lewis acid catalyst in an amount of from 0.05 to 1 part by weight relative to 1 part by weight of the copolymer particles, in the presence of an organic solvent. |