𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Influence of polymerization conditions on microstructure of norbornene-ethylene copolymers made using metallocene catalysts and MAO

✍ Scribed by Christer H. Bergström; Taito L. J. Väänänen; Jukka V. Seppälä

Publisher
John Wiley and Sons
Year
1997
Tongue
English
Weight
151 KB
Volume
63
Category
Article
ISSN
0021-8995

No coin nor oath required. For personal study only.

✦ Synopsis

When characterized with 13 C-NMR, it was found that norbornene-ethylene copolymers had a more complicated microstructure when dimethylsilyl bis(indenyl) zirconium dichloride was used as the catalyst compared to ethylene bis(indenyl) zirconium dichloride. One could see more block sequences but less alternating sequences. For both catalysts the highest amounts of block sequences were obtained for high norbornene concentrations, medium to high Al/Zr ratios, and low polymerization temperatures. There were also more alternating sequences for high norbornene concentrations and high polymerization temperatures. The isolated norbornene units (separated by more than one ethylene unit) were all exoconfiguration. No unsaturation was seen.

📜 SIMILAR VOLUMES

Influence of the polymerization conditio
Influence of the polymerization conditions on the rigidity of phenylnorbornene-ethylene copolymers made using ethylene bis (indenyl) zirconium dichloride and MAO
✍ Christer H. Bergström; Paul G. Starck; Jukka V. Seppälä 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 English ⚖ 203 KB 👁 1 views

When characterized with DMA it was found that Phenylnorbornene-ethylene copolymers with equivalent comonomer concentrations had very different storage moduli in the glassy state as well as glass transition temperatures. NMR analysis of the copolymers revealed that they had different ratios of Exo-an

Investigation of the microstructure of m
Investigation of the microstructure of metallocene-catalyzed norbornene–ethylene copolymers using NMR spectroscopy
✍ Christer H. Bergström; Bernd R. Sperlich; Juhana Ruotoistenmäki; Jukka V. Seppäl 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 English ⚖ 196 KB 👁 2 views

Norbornene-ethylene copolymers were prepared using the metallocene catalyst ethylene bis (indenyl) zirconium dichloride with MAO, and their microstructure was characterized with 1 H-NMR and 13 C-NMR methods. From a Cosy 1 H-NMR spectrum it was found that all norbornene units are enchained in the exo

Effects of polymerization conditions whe
Effects of polymerization conditions when making norbornene-ethylene copolymers using the metallocene catalyst ethylene bis (indenyl) zirconium dichloride and MAO to obtain high glass transition temperatures
✍ Christer H. Bergström; Jukka V. Seppälä 📂 Article 📅 1997 🏛 John Wiley and Sons 🌐 English ⚖ 128 KB 👁 1 views

Using 70 mol % norbornene in the monomer mixture before polymerization, the influences of different polymerization conditions were studied. It was found that by increasing the temperature from 10 to 70ЊC, the yield increased and the molecular weight decreased; and when increasing the ethylene pressu

Influence of the polymerization conditio
Influence of the polymerization conditions on the impact properties of metallocene-catalyzed copolymers of ethylene and aryl-substituted norbornenes with low exo/endo ratios
✍ Christer H. Bergström; Juhana Ruotoistenmäki; Erkki T. Aitola; Jukka V. Seppälä 📂 Article 📅 2000 🏛 John Wiley and Sons 🌐 English ⚖ 151 KB 👁 1 views

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