A series of symmetric and asymmetric binuclear α-diimine nickel(II) complexes toward ethylene polymerization were successfully synthesized and characterized by 1HNMR. All the catalysts were typically activated with MAO and displayed good activity at room temperature under 1atm ethylene pressure. The symmetric catalyst containing isopropyl on l...

Cationic waterborne polyurethane as a new dispersing polymer was synthesized by using relatively hydrophilic polyols. Dispersing cationic polyurethane (DCPU) nanocomposites were prepared using isophorone diisocyanate (IPDI), polyethylene glycol (PEG) with different molecular weights (Mn=200, 400, 600,and1000 g/mol), N-methyl diethanolamine (MDEA), dibutyltin dilaurate (DBTDL) and different perc...

there are described nanocomposites based on ultra high molecular weight polyethylene and graphite nanoplates prepared by in-situ polymerization method. it is carried out a comprehensive study of electric properties of these composites, including direct current (dc) and alternating current (ac) properties. there is explored dependence of the conductivity and dielectric permeability on filler con...

BACKGROUND Studies have suggested that cross-linked polyethylene bearings reduce wear rates from 40% to 100% compared with conventional polyethylene. However, the reduced mechanical properties of highly cross-linked polyethylene have the potential to be a limiting factor in device performance. We reviewed a series of retrieved acetabular liners with a fracture of the superior rim to assess the ...

The surface characteristics and friction behaviour of titanium Grade 2 with modified nitride (TiN, Ti2N) boride (TiB) compound layers were investigated. It was shown that during non-contact boriding in oxygen-containing medium titanium, the diffusion processes take place mainly by interscale mechanism; however, nitriding, besides traditional mechanism, grain boundary mechanism nitrogen atoms is...