A commercial SiO2 modified by the addition of a TiO2 layer on its surface and pore walls offers support for metallocene-based ethylene polymerization catalysts with 35% improved catalytic activity. The effect such modification catalyst particle fragmentation during reactions were assessed. This was performed exposing internal cross-section several Ti/SiO2-based metallocene particles, polymerize...

Activities during ethylene/1-hexene copolymerization were found to increase using the mixed titania/silica-supported MAO with rac-Et[Ind]2ZrCl2 metallocene catalyst. Energy Dispersive X-ray spectorcopy (EDX) indicated that the titania was apparently located on the outer surface of silica and acted as a spacer to anchor MAO to the silica surface. IR spectra revealed the Si-O-Ti stretching at 980...

The base-free dimethyl scandium complex supported by the bulky beta-diketiminato ligand ArNC((t)Bu)CHC((t)Bu)NAr (Ar = 2,6-(i)Pr(2)C(6)H(3), 1) reacts with various equivalencies of the strong organometallic Lewis acid B(C(6)F(5))(3) to give scandium alkyl cations. With 0.5 equiv, a monocationic mu-methyl dimer (2) was observed spectroscopically. Reaction with a further 0.5 equiv of borane gives...

Metallocene of zirconium were used as a catalyst for an insertion polymerization of 1-methylsilene directly into pre-ceramic precursor polyzirconocenecarbosilane (PZCS) during dechlorination of dichlorodimethylesilane by sodium, which exhibits high catalytic effectiveness with the maximum conversion ratio of polycarbosilane up to 91%. The average molecular weights of polymers synthesized are le...

Covalent organic framework (COF) particles with hydroxy groups and well-defined micropores have been synthesized used as novel carriers to load a metallocene catalyst—Cp2ZrCl2. The resulting supported catalyst, which had high specific surface area, demonstrated higher catalytic activity, better thermal tolerance, unique nanoconfinment effect during ethylene polymerization, producing polyethylen...

The space charge distribution in low-density polyethylene (LDPE) was measured with the pulsed electroacoustic (PEA) method. We used three types of LDPE: LDPE-L and LDPE-H were prepared by the high pressure process, and m-LDPE was polymerized with a metallocene catalyst. Space charge in LDPE strongly depended upon the electrode material. Semiconductive electrodes enhanced carrier injection into ...

Isotactic poly (1-butene), ipbu-1, was synthesized by using a metallocene catalyst. The thermodynamic phase behavior of polymer–organic solvents systems is very important in every polymer application.  In this paper, the solid–liquid equilibrium of ipbu-1 with different organic solvents (1-heptyne, cyclo octane) was studied by a mathematical model. By considering the experiments temperature...

Polyethylene/chrysotile nanocomposites with different amount (0.4 to 6.7 wt%) of filler were prepared by in situ polymerization method using the metallocene Cp2ZrCl2 as catalyst and methylaluminoxane (MAO) as co-catalyst. Previous to polymerization, raw chrysotile was treated by three different methods that used thermal treatment and acid leaching. In method A, raw chrysotile was treated therma...