A stereoregular alternating ethylene-styrene copolymer, also stretchable in fiber form, has been obtained with rac-isopropylidenebis( l-indenyl)zirconium dimethyldiamide activated by the methylalumoxane catalytic system. From X-ray diffraction fiber spectra, an isotactic structure has been assigned to this copolymer as well as the previously described stereoregular ethylene-styrene copolymers. The polymer has zigzag planar chain conformation with phenyl groups oriented perpendicularly to the chain axis. The crystallographic symmetry in B2/m. Lattice constants (monoclinic, unique axis c): a = 10.23, b = 15.53, c = 5.12 Angstrom; gamma = 98.6 degrees. The disagreement index for measured reflections is R-1 = 0.10.
Crystal structure of the stereoregular ethylene- alt - styrene copolymer synthesized with zirconocene based catalyst
OLIVA, Leone;TEDESCO, Consiglia;VENDITTO, Vincenzo;PROTO, Antonio
1999-01-01
Abstract
A stereoregular alternating ethylene-styrene copolymer, also stretchable in fiber form, has been obtained with rac-isopropylidenebis( l-indenyl)zirconium dimethyldiamide activated by the methylalumoxane catalytic system. From X-ray diffraction fiber spectra, an isotactic structure has been assigned to this copolymer as well as the previously described stereoregular ethylene-styrene copolymers. The polymer has zigzag planar chain conformation with phenyl groups oriented perpendicularly to the chain axis. The crystallographic symmetry in B2/m. Lattice constants (monoclinic, unique axis c): a = 10.23, b = 15.53, c = 5.12 Angstrom; gamma = 98.6 degrees. The disagreement index for measured reflections is R-1 = 0.10.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
