1,721,051 research outputs found
Theoretical investigation of new non-metallocene Column 4 octahedral catalytic species, and feed-back on heterogeneous Ziegler-Natta systems
No full textMelting behavior of hydrocarbon chain molecules with ionic end groups: prymary n-alchilammonium halides.
No full textStepwise melting behavior for a series of primary long chain n-alkylammonium chlorides was pointed out. A plastic phase, a smectic mesophase and a “clear” liquid possibly unisotropic were observed. The same trend seems to be common to other hydrocarbon molecules with ionic endgroups, including alkali metal n-alkanoates
Imagine polypropylene
No full textLinear polyethylene and isotactic polypropylene, the two largest-volume polymers on the market, were invented in the 1950s thanks to diverse mixes of serendipity, intuition and talent. After 70 years, a thoughtful revisitation of those ground-breaking discoveries can still be revealing and inspirational
HTE methods and results in PO catalysis and materials characterization
No full textHigh Throughput Experimentation (HTE) was originally introduced in olefin polymerization R&D as a discovery tool. In recent years, we spent a considerable effort to extend the scope of the HTE approach to mechanistic investigations. A high-performance polymerization platform (Freeslate PPR48) was integrated with state-of-art polymer characterization tools (including GPC, 13C NMR and A-CEF), and the resulting workflow was optimized for the fast acquisition of large structure-properties databases usable in QSAR studies. The workflow was successfully applied to Ziegler-Natta and molecular olefin polymerization systems and products thereof.(1)
In this presentation, we will illustrate case histories of increasing complexity, covering molecular kinetics as well as polymer characterization aspects
Theoretical investigation of new non-metallocene Column 4 octahedral catalytic species, and feed-back on heterogeneous Ziegler-Natta systems
No full textLiving" Propene Polymerization with Bis(phenoxyimine) Group 4 Metal Catalysts: New Strategies and Old Concepts
No full textOrigin of the Regiochemistry of Propene Insertion at Octahedral Column 4 Polymerization Catalysts
No full textBook of Abstracts-P6
Violet TiCl3-based catalyst: a revisitation
No full textThe performance of a second-generation "violet" TiCl3-based catalyst in propene polymerization is compared with that of first-generation TiCl3's and of supported MgCl2/TiCl4 "high-yield" systems. The results suggest that a few "adjustments" may be needed in the current views on the nature of the active species in such systems
Violet TiCl3-based catalyst: a revisitation
No full textThe performance of a second-generation "violet" TiCl3-based catalyst in propene polymerization is compared with that of first-generation TiCl3's and of supported MgCl2/TiCl4 "high-yield" systems. The results suggest that a few "adjustments" may be needed in the current views on the nature of the active species in such systems
Active species in heterogeneous Ziegler-Natta catalysts: "the father of all models"
No full textA general model of the catalytic species on the surface of heterogeneous Ziegler-Natta catalysts (either TiCl3-based or MgCl2-supported), based on the statistical analysis of their high-field 13C NMR "fingerprint" in the polymerization products, is presented and discussed
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