Mononuclear phenols substituted with tert-butyl, cyclohexyl or 1-phenylethyl groups as antioxidants in isotactic polypropylene

1978 ◽  
Vol 43 (10) ◽  
pp. 2578-2582 ◽  
Author(s):  
Jan Holčík ◽  
Pavel Čaučík ◽  
Jan Pospíšil
Keyword(s):  
Isotactic Polypropylene ◽  
Tert Butyl

A Rigid C1-Bridged Ansa-Zirconocene-Derived Catalyst System Suited for Stereoselective Low Molecular Weight Polypropylene Formation

1995 ◽  
Vol 50 (4) ◽  
pp. 469-475 ◽  
Author(s):  
Gerhard Erker ◽  
Christian Psiorz ◽  
Roland Fröhlich
Keyword(s):  
Molecular Weight ◽  
Fractional Crystallization ◽  
Isotactic Polypropylene ◽  
Catalyst System ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tert Butyl ◽  
Catalyst Systems

2,5-Hexanedione was converted into the bisfulvene 2, then treated with two molar equivalents of methyllithium to yield the [4-cyclopentadienylidene-4,7,7-trimethyl-4,5,6,7-tetrahydroindenyl] dilithio compound 4. Hydrolysis, followed by treatment with acetone/pyrrolidine, gave the corresponding fulvene system 5. Reaction of 5 with methyllithium followed by treatment with ZrCl4 furnished the ring-annulated C1-bridged ansa-metallocene 8, bearing a tert-butyl substituent at the Cp ring, as a 1:1 mixture of two diastereoisomers. Treatment of the fulvene 5 with LiAlH4 followed by ZrCl4 yielded the respective isopropyl-substituted ansa-metallocene diastereomers 9a and 9b. Complex 9b was separated by fractional crystallization and characterized by X-ray diffraction. Complexes 8 and 9 provide active homogeneous Ziegler-type catalyst systems upon activation with excess methylalumoxane producing low molecular weight isotactic polypropylene with high catalyst activities.

Properties of nanocomposites based on isotactic polypropylene and high-pressure polyethylene with metal-containing nanofillers

2020 ◽  
pp. 59-64
Author(s):  
N. I. Kurbanova ◽  
◽  
T. M. Gulieva ◽  
N. Ya. Ischenko ◽  
◽  
...  
Keyword(s):  
High Pressure ◽  
Synergistic Effect ◽  
Polymer Matrix ◽  
Isotactic Polypropylene ◽  
Rheological Parameters ◽  
Mechanochemical Method ◽  
X Ray ◽  
Effect Of Additives ◽  
High Pressure Polyethylene ◽  
Properties Of Composites

The effect of additives of nanofillers (NF) containing nanoparticles (NP) of copper oxide, stabilized by a polymer matrix of maleized polyethylene (MPE), obtained by the mechanochemical method, on the properties of composites based on isotactic polypropylene (PP) and high-pressure polyethylene (PE) was studied by X-ray phase (XRD) and thermogravimetric (TGA) analyzes. The enhancement of strength, deformation, and rheological parameters, as well as the thermo-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is due to the synergistic effect of the interaction of copper-containing nanoparticles with anhydride groups of MPE. It is shown that nanocomposites based on PP/PE/NF can be processed both by pressing and injection molding and extrusion, which expands the scope of its application.

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