Molecular structure of styrene-ethylene copolymers prepared over different kinds of titanium catalysts

• Published in: Materials letters Vol. 33; no. 5; pp. 301 - 304
• Main Authors: Chu, Kyung-Jun, Ha, Jin-Wook
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 1998; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Molecular structure; Monocyclopentadienyl titanium catalyst; None-cyclopentadienyl titanium catalyst; Organic polymers; Physicochemistry of polymers; Properties and characterization; Structure, morphology and analysis; Styrene—ethylene copolymer; Monocyclopentadienyl titanium catalyst; Styrene—ethylene copolymer; Molecular structure; None-cyclopentadienyl titanium catalyst; Titanium complex; Experimental study; Syndiotactic polymer; Complex catalyst copolymerization; Titanium IV Chlorides; Ethylene copolymer; Chloro complex; Hapto complex; Aluminium Organic compounds; Microstructure; Stereospecific polymerization; Comparative study; Styrene copolymer
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(97)00119-5

The copolymerization of styrene and ethylene was carried out in the presence of two different catalyst systems; i.e., CpTiCl 3-methyl aluminoxane and TiCl 4-methyl aluminoxane. The structure of polymers was investigated with 13C-NMR (nuclear magnetic resonance) spectroscopy, DSC (differential scanning calorimetry) and XRD (X-ray diffractometry). From the analyses of the 13C-NMR and XRD data, the molecular structure of the styrene-ethylene copolymer produced over the CpTiCl 3 catalyst system seems to indicate that the ethylene units are randomly distributed in the syndiotactic polystyrene main chain as defects. Whereas the molecular structure of the styrene-ethylene copolymer produced over the TiCl 4 catalyst seems to indicate that the styrene units are randomly distributed in the polyethylene main chain as defects.