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6619786 
Journal Article 
Isospecific homo- and copolymerization of styrene with ethylene in the presence of VCl3, AlCl3 as catalyst 
Ribeiro, MR; Portela, MF; Deffieux, A; Cramail, H; Rocha, MF; , 
1996 
1 
Macromolecular Rapid Communications
ISSN: 1022-1336
EISSN: 1521-3927 
WILEY-V C H VERLAG GMBH 
WEINHEIM 
17 
7 
461-469 
English 
WOS:A1996VA04100004 
The homopolymerization of styrene and its copolymerization with ethylene in the presence of a vanadium-based supported catalyst, {VCl3, 1 AlCl3}, associated to triethylaluminium is examined. As indicated by means of C-13 nuclear magnetic resoance and differential scanning calorimetry analysis, the homopolystyrenes obtained present a highly isotactic microstructure and are semicrystalline (melting temperature 220 degrees C).In the case of styrene/ethylene random copolymerization, the formation of both, polyethylene blocks and isotactic polystyrene sequences was identified by analysis of the crude polymer. Solubility characteristics and structural characteristics from nuclear magnetic tesonance spectra of these products support the formation of copolymers with ethylene and isotactic styrene blocks rather than that of two distinct homopolymers.