Junichi Imuta

Characterization of PP prepared with the latest metallocene and MgCl2-supported TiCl4 catalyst systems

A novel metallocene, rac-Me2Si[2-n-Pr-4-(9-Phenanthryl)-Ind]2ZrCl2, was synthesized and employed for propylene polymerization in conjunction with Ph3CB(C6F5)4 as a cocatalyst. The resulting polypropylene (m-PP) shows 99.6 % of mmmm by 13C NMR and 162.8 °C of melting temperature (Tm) by DSC. In addition, m-PP was compared with the polypropylene (Ti-PP) produced by our latest MgCl2-supported TiCl4 catalyst system, which shows 99.0 % of mmmm and 165.7 °C of Tm, by TREF analysis. TREF indicated that m-PP has narrower stereo-regularity distribution than Ti-PP and Tm of the fraction eluted from m-PP at the highest temperature is 163.6 °C, while that from Ti-PP reaches to 167.3 °C. The individualities of both catalyst systems are discussed.

Biomimetic one-pot synthesis of nucleotide phosphates

Abstract A strongly hydrophobic rigid diammonium, 1, an efficient extracting and transporting phase transfer reagent with high specificity for the pyrophosphate grouping, was used to synthesize ADP, ATP or ADP-NH 2 in a hydrophobic medium. Thus, practically pure ADP-NH 2 was obtained in 65% yield within 2 min.

Unique Flowability Behavior of Ethylene Copolymers Produced by a Catalyst System Comprising Ethylenebis(indenyl)hafnium Dichloride and Aluminoxane

This paper relates to novel ethylene copolymers and a process for preparing the same and more particularly to novel ethylene copolymers excellent in flowability in spite of the fact that they are narrow in molecular weight distribution (Mw/Mn) in comparison with conventionally known ethylene copolymers, and to a process for preparing the same. In another aspect, this paper relates to olefin polymerization catalysts capable of polymerizing olefins with excellent comonomer incorporation and capable of giving olefin polymers having high molecular weights.