Norbornene–ethylene copolymers were prepared using the metallocene catalyst ethylene bis (indenyl) zirconium dichloride with MAO, and their microstructure was characterized with 1H‐NMR and 13C‐NMR methods. From a Cosy 1H‐NMR spectrum it was found that all norbornene units are enchained in the exo‐configuration. The sequence distribution of norbornene units was investigated using 13C‐1H correlations, hmqc for one‐bond correlations, and hmbc for two‐ or three‐bond correlations. It was shown that norbornene diads were formed at a high norbornene content (45 mol %). When further increasing the norbornene incorporation (66 mol %) a number of new signals were obtained. A Cosy 1H‐NMR spectrum revealed a new crosspeak which, according to the corresponding 13C‐NMR shifts (hmqc), correlated well with a terminal unit of a trimer of norbornene. This means that at very high norbornene contents, norbornene triads can be formed. Because the formation of isotactic norbornene triads is very difficult to understand from a sterical point of view, an epimerization process causing stereoirregularities in the norbornene triad is proposed. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1633–1638, 1998

When testing copolymers of ethylene and aryl-substituted norbornenes with the Charpy impact method it was found that under certain polymerization conditions their impact properties increased with increasing polymerization time. It was also found that this improvement on impact properties was due to increasing exo/endo ratios of the incorporated aryl-substituted norbornene comonomers. This effect is important because impact-resistant copolymers can be made using aryl-substituted norbornene comonomers with low exo/endo ratios, which are more easily synthesized and purified.

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When testing copolymers of ethylene and aryl‐substituted norbornenes with the Charpy impact method it was found that under certain polymerization conditions their impact properties increased with increasing polymerization time. It was also found that this improvement on impact properties was due to increasing exo/endo ratios of the incorporated aryl‐substituted norbornene comonomers. This effect is important because impact‐resistant copolymers can be made using aryl‐substituted norbornene comonomers with low exo/endo ratios, which are more easily synthesized and purified. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1108–1117, 2000