Propene polymerization with isotactic (iso)-specific C₂-symmetric rac-Me₂Si(2-Me-Benz(e)-Ind)₂ZrCl₂ (1) and rac-Me₂Si(2-Me-4-Ph-1-Ind)₂ZrCl₂ (2) were conducted under various conditions for achieving iso-specific living polymerization of propene. When Complex 1 was activated with trialkylaluminum-free modified methylaluminoxane (dMMAO) at -40 °C, the number-average molecular weight (Mn) linearly...

Polymerizations of racemic mixtures of epoxides or episulfides may lead to stereoregular polymers through a stereoselective process, and to optically active polymers through a stereoelective process that gives either atactic or isotactic polymers. Monomers that have been most studied are propylene oxide, propylene sulfide and t-butyl thiirane, and their polymerization with insoluble initiators ...

in this investigation, the mechanical properties of the blends of blown bitumen110/10, heavy vacuum slops (h.v.s), bitumen 60/70 penetration grade and isotactic polypropylene (ipp) were studied for the first time. our results showed that modulus varies non-linearly and at certain asphaltenes contents a peak appears. considering these phenomena it is revealed that in the absence of ipp, interact...

The crystalline stereocomplexed polycarbonates can be prepared by mixing enantiopure polymers with opposite configuration, which derived from the asymmetric copolymerization with CO2 using enantiopure catalyst or/and chiral epoxides. Herein, we develop a powerful strategy for producing crystalline intramolecular stereocomplexed polycarbonates from racemic catalysts, which possess similar therma...

The film thickness dependence of crystal growth is investigated for isotactic polystyrene (it-PS) in thin films, the thickness of which is from 20nm down to 4nm. The single crystals of it-PS grown at 180 in the ultrathin films show the morphology typical in the diffusion-controlled growth: dense branching morphology (DBM), fractal seeweed (FS). The characteristic length of the morphology, i.e. ...

A general model to calculate the structure of a smectic to nematic-like order in polymer systems is proposed. The model is limited to well-aligned molecules with respect to each other. It is especially suited for systems where the packing between neighboring chains is described by liquid-like disorder with axial registration in the chain-axis direction. In such a case the diffraction pattern fr...