| 摘要 |
A solution polymerization process for the preparation of a polymeric material having a weight average molecular weight from 5,000 to 20,000,000 and comprising cross-linked particles which are capable of forming a sol in the reaction solvent, which process comprises: (i) polymerizing one or more monomers, the or at least one of which is a cross-linking agent, in a solvent which (a) has a solubility parameter from 2.5 cal+E,fra 1/2+EE ml+E,fra -3/2+EE below to 1.0 cal+E,fra 1/2+EE ml+E,fra -3/2+EE above the solubility parameter of the bulk polymeric material and (b) is of the same or adjacent hydrogen bonding group as the bulk polymeric material; (ii) monitoring the polymerization until polymeric material as herein defined is obtained; and (iii) terminating the polymerization before gelation is observed.
|
