Phillips catalysts synthesized over various silica supports: Characterization and their catalytic evaluation in ethylene polymerization
Journal Title: Polyolefins Journal - Year 2016, Vol 3, Issue 1
Abstract
Ethylene polymerization was carried out using Phillips chromium catalyst based on silica supports such as silica aerogel, SiO2 (Grace 643), and titanium modified SiO2 (G 643), and the results were compared with other catalysts based on SiO2 (Aldrich), SBA-15(Hex), SBA-15(Sp) and MCM-41. A combination of TGA, DSC, XRD, nitrogen adsorption, SEM, ICP, FTIR and other analyses were used to characterize the materials. The results showed that the chromium was successfully introduced into silica supports. Shish-kebab polyethylene was prepared via in situ ethylene polymerization with the Cr/SiO2 (G 643) and Cr/Ti/SiO2 (G 643) catalytic systems. A comparison between different types of catalysts revealed that the polymerization activity of Cr/SiO2 (G 643) was significantly increased to 191 kg PE (g Cr)-1 h-1 due to the higher pore volume and pore diameter of Grace silica compared to the other supports. Also, the polymerization activity of the Cr/SiO2 (G 643) catalyst was significantly improved by Ti-modification.
Authors and Affiliations
Ebrahim Ahmadi, Zahra Mohamadnia, Sajjad Rahimi, Mohammad Hasan Armanmehr, Seyyed Mohammad Heydari, Mahmood Razmjoo
Keywords
Related Articles
- EP ID EP283167
- DOI 10.22063/POJ.2016.1268
- Views 119
- Downloads 0
Study on the fouling behavior of HDPE/PE-g-MA/EVA blend membrane fabricated via thermally induced phase separation method
In this study, neat HDPE and HDPE/PE-g-MA/EVA blend membranes were fabricated via thermally induced phase separation (TIPS) method and their fouling behaviors were examined using filtration of BSA protein. Membranes were...
The relationship among changes in microstructure, active sites behavior and properties in the propylene polymerization with a 4th generation Ziegler-Natta catalyst
Three polypropylene samples (1-3) were synthesized with a 4th generation Ziegler-Natta catalyst in the presence of cyclohexyldimethoxymethylsilane (donor c), dicyclopenthyldimethoxysilane (donor d) and diisopropyldimetho...
Probing into morphology evolution of magnesium ethoxide particles as precursor of Ziegler-Natta catalysts
Mg(OEt)2 with spherical morphology is one of the most important precursors for the preparation of industrial Ziegler-Natta catalysts. In the present article, morphology evolution of Mg(OEt)2 particles is studied in the c...
Inhibition effect of polyvinyl butyral on crystallization of polypropylene
In this work, a series of polypropylene/polyvinyl butyral (PP/PVB) blends were prepared by melt-blending process, at PVB loadings 3 wt%, 10 wt%, and 30 wt%. The effects of PVB on crystallization behavior of PP were inves...
Development of a rheological model for polymeric fluids based on FENE model
Rheological models for polymer solutions and melts based on the fnitely extensible non-linear elastic (FENE) dumbbell theory are reviewed in this study. The FENE-P model that is a well-known Peterlin approximation of the...