| abstract |
A process for preparing a modified, amorphous poly-(2,6-dimetyl-p-oxyphenylene) (PPO) comprises:n * metallating PPO by a metallating agent, and * functionalizing such a metallated PPO by the reaction with a trialkylsilyl halide and/or ethylene oxide; and is characterized in that the reaction of metallation is carried out in an inert liquid vehicle which contains PPO in an at least partially suspended solid form, by operating under metallating conditions and gradually adding said metallating agent to such a suspension, either continuously or as discrete portions.n Dependently on the functionalizing agents used, and on the sequence of addition thereof, the process makes it possible PPO polymers to be obtained, which are modified with trialkyl-silyl, hydroxyethylene and/or ethyleneoxy-trialkyl-silyl functional groups. They are particularly suitable for preparing flat membranes, including asymmetrical membranes, for the separation of gas mixtures. |