Abstract: A continuous process for the solution polymerization of appropriate polycycloolefins in a ROMP zone to obtain a processable ROMP homo- or copolymer in solution, and subsequent hydrogenation of the ROMP (co)polymer without removing the residual ROMP catalyst and co-catalyst, provides an optical product having a mol wt M.sub.w in the range from 50,000-300,000 and polydispersity M.sub.w /M.sub.n in the range from 1.3-5.0, more preferably from 1.3-3, the lower the polydispersity the more desirable the physical properties of the (co)polymer.

Abstract: Process for preconcentrating polymer cement normally containing about 15% solids comprising mixing therewith an amount of a hydrocarbon nonsolvent liquid sufficient to form a two-phase system but insufficient to precipitate the polymer, and separating the two phases; the polymer cement is a honey-like solution of a polymer prepared by ring opening polymerization of at least one monomer containing the norbornene group in a nonpolar hydrocarbon solvent; the upper phase being a thin hydrocarbon liquid comprising nonsolvent, a substantial portion of the nonpolar solvent in the polymer cement, and impurities, and the lower phase being a preconcentrated polymer cement containing at least 20% solids.

Abstract: At least one cycloolefin monomer containing the norbornene group is polymerized by ring opening polymerization in a hydrocarbon diluent selected from C.sub.4 to C.sub.6 alkanes and isooctane that is a solvent for the monomer(s) but a nonsolvent for the resulting polymer, in the presence of a dispersant selected from terpolymers of ethylene, propylene, and dicyclopentadiene, copolymers of styrene and butadiene, and homopolymers of butadiene, whereby a dispersion of polymer particles in the diluent is produced having a particle size that is substantially smaller than polymer particles prepared in absence of the dispersant, which polymer particles, in the preferred embodiment, do not settle out almost immediately after stopping agitation and result in a much cleaner reactor than in slurry polymerization systems where dispersants are not used.