Abstract: The specification discloses a method for making DCPD based resins that have essentially unimodal molecular weight distributions. The method comprises polymerizing dicyclopentadiene monomer in the presence of an organic sulfur compound which is effective to control the molecular weight distribution of the polymerized product. For end-use performance in inks, adhesives, coatings and other related areas, the invention provides dicyclopentadiene based resins having molecular weight distributions which effectively enhance the resin solubility and compatability in various formulations.

Abstract: The present invention provides a method for the polymerization or copolymerization of a monomer or blend of monomers selected from the group consisting of C-10 terpenes, vinyl aromatics and C-5 dienes that comprises complexing a Lewis acid with an organic ketone to produce a catalyst complex. The monomer or blend of monomers is added to the catalyst complex producing the reaction mixture. The reaction mixture is maintained at a temperature of between 10.degree. C. and 60.degree. C. and, when the reaction is complete, is quenched with water. The polymerized or copolymerized resin is then recovered.