In the first part of this study, olefins (ethylene or propylene) and different kinds of silane monomers were copolymerized with metallocene/MAO catalysts. The copolymerization of 7-octenyldimethylphenylsilane and olefin was conducted with Et(Ind)2ZrCl2/MAO, Me2Si(2-Me-Ind)2ZrCl2/MAO and Me2Si(2-Me-4-Ph-1-Ind)2ZrCl2/MAO catalyst complexes, and the results (catalyst activity, microstructure of the copolymer) were found to be comparable with the parallel copolymerizations of olefin and 1-alkenes (1-decene, 1-dodecene). In addition, the copolymerization performances of vinyl- and allyltrimethylsilane were studied using Et(Ind)2ZrCl2/MAO. Due to the electronic influence of silicon, these comonomers acted as strong chain transfer agents and the synthesized ethylene/silane copolymers suffered from low molar mass. Further on, increasing the functionality of polyolefins, the post treatment approach was studied. New routes for silane functionalized polyolefins were developed, where the pendant phenylsilane side groups in the polyolefin-co-7-octenyldimethylphenylsilane (PE-co-SiPh, PP-co-SiPh) copolymer were post treated to fluoro-, chloro-, methoxy- or ethoxysilane moieties. Beside of that, the hydrosilylation reaction was exploited on polyethylene-co-1,7-octadiene, and polyethylene with pendant chloro- or ethoxysilane functionalities were synthesized via that route. As a result, all of these post treatment steps were performed with high conversion and without influencing drastically on the molar mass of the polymers. In the last part of this thesis, these functionalized polyolefins were tested as reactive compatibilizers in particulate filled polyolefin composites. The properties of these composites, especially the toughness, were influenced with a small amount of the compatibilizer. In addition, the filler/matrix interphase in PE/ATH(aluminumtrihydroxide) composite and a new fracture mechanism in PP/rubber/microsilica ternary composite were discovered. Finally, also the untreated polyolefin-co-7-octenyldimethylphenylsilane (PE-co-SiPh and PP-co-SiPh) showed high affinity towards microsilica filler. It became clear that the weakly interacting phenylsilane moiety can react in a manner similar to the highly reactive halo- and alcoxysilanes towards the hydroxyl groups at the surface of microsilica filler.
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