Catalytic emulsion polymerization of ethylene with nickel catalysts in the presence of silica nanoparticles affords stable dispersions of silica/polyethylene nanocomposite particles. The modification of the surface of silica particles by grafting upon their surface of octenylor octylsilanes is a prerequisite for obtaining composites. Different morphologies of composites particles were observed ...

We report the design, synthesis, morphology, phase behavior, and mechanical properties of semicrystalline, polyolefin-based block copolymers. By using living, stereoselective insertion polymerization catalysts, syndiotactic polypropylene-block-poly(ethylene-co-propylene)-block-syndiotactic polypropylene and isotactic polypropylene-block-regioirregular polypropylene-block-isotactic polypropylene...

Bulky 2-pyridinemethanamine nickel complex activated by MAO was used as a catalyst to conduct longstanding living ethylene polymerization under atmospheric pressure to produce branched polyethylene.

The present research focuses on investigation of the catalytic behaviors of MgCl₂-SiO₂/TiCl₄/THF Ziegler-Natta (ZN) catalysts with fumed SiO₂ variously treated with silane compounds. The non-treated silica (NTS) and other silicas treated with dimethylsilicone fluid (TSDMSF), dimethyldichlorosilane (TSDMDCS), and hexamethyl-disilazane (TSHMDS) were employed. It was found that the Cat-TSDMDCS and...

Ring-opening metathesis polymerization (ROMP) is one of the most widely used polymerizations. With the development of well-defined catalysts, such as (t-BuO)2(ArN)Mo=CH(t-Bu) (1), Cl2(PCy3)2Ru=CHPh (2), and Cl2(PCy3)(IMesH2)Ru=CHPh (3), more controlled polymer structures have been obtained by either living polymerization or chain transfer induced polymerization. However, these catalysts suffer ...

The results of decades of studies on the Phillips chromium (Cr)/silica polymerization catalyst are briefly summarized. The application of several characterization methods has allowed a detailed knowledge of the structure and reactivity of Cr centres to be obtained. In particular, many aspects of this apparently simple single-site catalyst, including the heterogeneity, the modification of the li...