Method for preparing norbornene based addition polymer containing ester or acetyl functional group

A method, comprising:

• contacting a norbornene-based monomer having an ester or acetyl group with a catalyst system comprising:
• i) a Group X transition metal compound represented by M(R)2, wherein M is a Group X metal and R is a ligand selected from the group consisting of acetate, and acetylacetonate (R“C(O)CHC(O)R”), wherein each of R″ is hydrogen;
• C1 to C20 linear or branched alkyl, alkenyl, or vinyl;
• C5 to C12 cycloalkyl substituted with hydrocarbon or unsubstituted;
• C6 to C40 aryl substituted with hydrocarbon or unsubstituted;
• C6 to C40 aryl having hetero atom;
• C7 to C15 aralkyl substituted with hydrocarbon or unsubstituted;
• or C3 to C20 alkynyl;
• ii) a compound comprising a neutral Group XV electron donor ligand having a cone angle of at least 160°;
• and
• iii) a salt capable of offering an anion that can be weakly coordinated to the i) transition metal,
• in solvent to conduct an addition polymerization;
• and
• forming a norbornene-based addition polymer having a polar group of ester or acetyl having a number average molecular weight (Mn) of 10,000 to 1,000,000, which is a norbornene-based homopolymer comprising an ester or acetyl group or a copolymer of norbornene-based monomers comprising different ester or acetyl groups.