单活性中心催化剂催化烯烃聚合研究-高分子化学与物理专业论文.docxVIP

单活性中心催化剂催化烯烃聚合研究 THE STUDY OF SINGLE SITE CATALYSTS AS CATALYSTS FOR OLEFIN POLYMERIZATION Abstract Two different types of single-site catalyst were studied in this thesis, namely metallocene catalysts and late transition metal catalyst. The polymerizations of styrene and ethylene were carried out using the former complexes activated with methylalminoxane (MAO), and The polymerizations of norbornene were performed using the later catalysts. Novel (μ-Oxo) dinuclear metallocene titanium complex, which were used to catalyse the polymerization of styrene with MAO as cocatalyst. The effects of reaction conditions on the polymerization results were systematically investigated, such as molar ratio of MAO to catalyst, reaction time, temperature, and solvent species, on the polymerization of styrene. The resulted polymer were characterizate by DSC, FT-IR, GPC, which were proved as isotactic polystyrene, whose isotacticity is up to about 90%, and the catalytic activity is up to 3.36×106 g PS/(mol·h). In addition, four kinds of Nickel-based complexes bearing o-hydroxyaryl N-heterocyclic carbenes [C,O] bidentate ligands and five kinds of Palludium-based complexes bearing o-hydroxyaryl N-heterocyclic carbenes [C,O] N, N-dimethyl benzyl amine ligands were used to catalyse the polymerizations of norbornene activated with methylalminoxane (MAO). The effects of reaction conditions on the polymerization results were systematically investigated for catalyst Ⅲ and Ⅴ, such as molar ratio of MAO to catalyst, reaction time, and temperature on the polymerization of norbornene. The polymer were characterizated by FT-IR and TGC, and by which we can confirmed that the polymerization occurred via vinyl-addition type polymerization (i.e. a 2,3-linked polymer). The thermo-gravimetric analysis showed that all of the polymers were stable about 400 oC under nitrogen. The catalytic activity is up to 8.87×106 g PNBE/(mol·h) and 4.38×107g PNBE/(mol·h), respectively. ii 河北工业大学硕士学位论文 KEY WORDS: (μ-Oxo)