Results 31 to 40 of about 856 (180)

Síntese de catalisadores Ziegler-Natta: algumas rotas e suas dificuldades Synthesis of Ziegler-Natta catalysts: some routes and their difficulties

Química Nova, 1997
The Ziegler-Natta catalyst and the polymerization thereof are systems which require careful handling and special treatment of chemicals. In spite of the use of inert atmosphere and dry chemicals, some Ziegler-Natta systems may present low activities or ...
Thaís H. S. Costa, Marcos A. S. Costa, Luiz Claudio de Santa Maria, Fernanda M. B. Coutinho, Neusa M. T. Pires   +4 more
doaj   +1 more source

Characterization of phthalate internal donor in MgCl2 supported Ziegler-Natta catalyst by solid state 13C NMR [PDF]

Polyolefins Journal, 2022
Ziegler-Natta catalyst for propylene polymerization, which TiCl4 and di-alkyl phthalate were supported on MgCl2, was analyzed by solid state 13C NMR. It was confirmed that the spin-lattice relaxation time (“relaxation time” hereafter) of carbonyl group ...
Masayoshi Saito, Toshiya Uozumi, Masahide Murata, Takuo Kataoka, Riichiro Chujo   +4 more
doaj   +1 more source

Determination of Optimal Reaction Temperature and Hydrogen Amount for Propylene Polymerization by a Mathematical Model [PDF]

Kemija u Industriji, 2019
Regarding the complexity of Ziegler-Natta catalyst kinetics in polypropylene polymerization, so far, there is no adequate model to determine the best process conditions for predicting average molecular weight and dispersity as the most crucial final ...
Gholam Hossain Varshouee, Amir Heydarinasab, Ali Vaziri, Seyed Mehdi Ghafelebashi Zarand   +3 more
doaj   +1 more source

POLYMERIZATION OF STYRENE USING ZIEGLER – NATTA CATALYST TYPE TICL4/MGCL2 – EB /ALET3 [PDF]

مجلة جامعة الانبار للعلوم الصرفة, 2013
In this study Ziegler – Natta catalyst was prepared which is a multi component catalytic system composed of, titaniumtetrachloride (TiCl4) as a active material, anhydrous magnesium chloride MgCl2 as support (carrier) which distribute the active material,
AYAD A. UTTAR, ALI S. ABED
doaj   +1 more source

In situ stabilization of polypropylene by lignin using a Ziegler-Natta catalyst [PDF]

Polyolefins Journal, 2014
A fourth-generation Ziegler-Natta catalyst was prepared to synthesize polypropylene (PP), which was stabilized by in situpolymerization employing lignin as antioxidant.
Maria Marques, Renato Oliveira, Rafael Araujo, Bruno Amantes   +3 more
doaj   +1 more source

Visible‐Light Driven Acetylene Semi‐Hydrogenation to Ethylene With a Copper Photosensitizer and a Cobaloxime Catalyst

Chemistry – A European Journal, EarlyView.
A fully noble‐metal‐free photocatalytic system that couples cobaloxime catalysis with Cu photosensitizer for HAT‐driven acetylene‐to‐ethylene conversion is reported. ABSTRACT The purification of ethylene streams from acetylene impurities remains a key industrial challenge, for which light‐powered strategies are emerging as sustainable alternatives to ...
Anna Fortunato, Sharon Silloni, Brando Adranno, Marianna Barbieri, Luka Đorđević, Francesca Arcudi   +5 more
wiley   +1 more source

One century of teaching, research, and innovation in chemical engineering in Mexico: The role of chemical engineering in the background and future of polymer science and industrial production in Mexico

The Canadian Journal of Chemical Engineering, EarlyView.
Timeline of key academic milestones and individuals that shaped chemical engineering at FQ‐UNAM and in Mexico. Abstract One hundred years after the beginning of the teaching of Chemical Engineering in Mexico, which started in 1925 in the former National School of Chemical Sciences, currently Faculty of Chemistry (FQ) at National Autonomous University ...
Patricia Pérez‐Salinas, Alberto Rosas‐Aburto, Eduardo Vivaldo‐Lima   +2 more
wiley   +1 more source

Potential of Thermoset Polyolefins for FRP Concrete Reinforcing Bars

Polymer Composites, EarlyView.
Overview of XLPO and pDCPD resins for FRP reinforcing bars, highlighting resin chemistry, key performance characteristics, fiber sizing interactions, and principal degradation mechanisms in concrete environments. ABSTRACT Although thermoset polyolefins offer resistance to hydrolytic degradation and favorable processing characteristics, their potential ...
Osama Omar, Farzaneh Mahmoudi, Leonidas G. Bachas, Francisco De Caso, Brahim Benmokrane, Antonio Nanni   +5 more
wiley   +1 more source

Oxidative Stability and Rheological Features in Recycled Composites Based on Postconsumer Polypropylene and Antioxidant‐Loaded Silicas

Polymer Engineering &Science, EarlyView.
Role of antioxidant supported on MCM‐41 and nano‐silica in enhancing oxidation induction time (OIT) and nucleation performance. ABSTRACT Plastic recycling efforts are hindered by the reduction of material properties in recyclates stemming from oxidative degradation of their polymeric chains.
Enrique Blázquez‐Blázquez, Kalman B. Migler, Tamara Díez‐Rodríguez, María L. Cerrada, Ernesto Pérez   +4 more
wiley   +1 more source

Speciation, Structural Refinement, and Distribution of Ti Sites in Titanium Silicalite‐1 From 47/49Ti NMR Crystallography at 28.2 Tesla

Angewandte Chemie, Volume 138, Issue 15, 6 April 2026.
Titanium silicalite‐1 (TS‐1), used in industrial selective oxidation processes, depends on specific, yet still unresolved Ti sites, dispersed within the framework of an MFI‐zeolite. Applying high field (28.2 T) 47/49Ti NMR and 17O NMR spectroscopy for an array of TS‐1 catalysts enables the development of an NMR crystallography protocol and the ...
Christoph J. Kaul, Jonas Koppe, Lukas Lätsch, Michael Wörle, Sadig Aghazada, Jacob B. Holmes, Christina Wartmann, Mingji Zheng, Albrecht Berkessel, Trees De Baerdemaeker, Andrei‐Nicolae Parvulescu, Karsten Seidel, J. Henrique Teles, Alexander V. Yakimov, Christophe Copéret   +14 more
wiley   +2 more sources