IMPROVEMENTS IN THE POLYMERIZATION OF NORBORNENE-TYPE CYCLOOLEFINS

摘要

A method of preparing a thermoset, cross-linked polymer of a norbornene-type monomer - particularly dicyclopentadiene - is disclosed wherein a reactant stream containing a metathesis catalyst is combined with a second reactant stream containing an activator, and the combined streams are immediately injected into a mold wherein polymerization and cross-linking take place to form a shaped object. The method is characterized by a two part activator comprised of dialkylaluminum chloride or a trialkyl aluminum compound as one part and a dialkylaluminum iodide as the second part. The two part activator delays the occurrence of cross-linking, thereby allowing a somewhat longer time for transfer of the combined streams to the mold and distribution thereof throughout the mold. It also leads to more complete polymerization.