Transition‐metal‐catalyzed vinyl addition polymerizations of norbornene derivatives with ester groups

Norbornene derivatives containing ester substituents were submitted to Pd(II)-catalyzed vinyl addition polymerization. The transition metal catalyst was found to tolerate the ester functionality. However, the rate of polymerization was reduced in comparison to the polymerization of norbornene. The polymerization of the pure exo-isomers produced substantially higher yields than reactions of monomers containing a high proportion of the corresponding endo-isomer. By varying the ester substituent, amorphous polymers with glass transition temperatures over the range of −40 to 268°C were synthesized. An approximately linear relationship of molecular weight to monomer conversion was established, and the non-uniformity remained narrow (Mw/Mn ≈ 1,15 – 1,25) until high conversions for several of the exo-isomers studied. This indicates that both chain transfer and chain termination are rare.