Results 11 to 20 of about 6,865 (263)

Direct Carboboration of Aryl Alkenes with Stable Organoborons Through Ziegler-Type Addition. [PDF]

Adv Sci (Weinh)
The direct carboboration of vinyl arenes with benzylic boronates has been achieved using KOtBu as the catalyst. Vinylcyclopropanes and vinylcyclobutane also participate in this reaction, yielding the corresponding 1,5‐ and 1,6‐carboboration products.
Yang M, Chen S, Li D, Gao L, Wang G, Li S.   +5 more
europepmc   +2 more sources

Probing the Interaction of Diester Internal Donors (ID) with AlEt₃ on Ziegler-Natta Surfaces: A Comparison Between Binary (MgCl₂/ID) and Ternary (MgCl₂/ID/TiCl₄) Formulations [PDF]

Molecules
Organic electron donors are essential components of Ziegler-Natta (ZN) catalysts to produce isotactic polypropylene. In particular, aromatic or aliphatic diesters are widely used as ‘Internal Donors’ (ID) in MgCl2/ID/TiCl4 precatalyst formulations ...
Felicia Daniela Cannavacciuolo, Giuseppe Antinucci, Roberta Cipullo, Vincenzo Busico   +3 more
doaj   +2 more sources

Effect of EtOH/MgCl2 Molar Ratios on the Catalytic Properties of MgCl2-SiO2/TiCl4 Ziegler-Natta Catalyst for Ethylene Polymerization [PDF]

Molecules, 2011
MgCl2-SiO2/TiCl4 Ziegler-Natta catalysts for ethylene polymerization were prepared by impregnation of MgCl2 on SiO2 in heptane and further treatment with TiCl4.
Piyasan Praserthdam, Supanan Patthamasang, Bunjerd Jongsomjit   +2 more
doaj   +2 more sources

Understanding the activity and stability of Lewis acid-modified Ziegler–Natta catalysts for the sustainable production of polypropylene

Journal of Taibah University for Science
Cleaner polymer production involves minimizing environmental impact by using efficient catalysts and eco-friendly synthesis methods. Identifying active and stable catalysts is essential.
Rafik Rajjak Shaikh, Yodsamol Sainu, Supareak Praserthdam, Piyasan Praserthdam   +3 more
doaj   +2 more sources

ESR Studies on Ziegler-Natta Catalyst Systems

The Journal of the Society of Chemical Industry, Japan, 1970
各種 TiCl3 の ESR 測定を行なった。TiCl3 (A型あるいはH型) では, TiCl3 (AA型) に見られるような g 値 1.94 の鋭い収は認められなかった。しかし, TiCl3 (A型あるいはH型) をボールミル磨砕した試料からは, g 値 1.94 の吸収が認められた。 さらに Ticl3 (A型) に, オレフィンあるいはアルキルアルミニウムを添加するとこの吸収が出現する。TiCl3 (AA型) に対する各種アルキルアルミニウムの影響を ESR で調べた。g 値 1.97 の吸収強度は, 重合活性序列 AlEt3>ALEt2Cl>AlEtCl2≒0 と非常に良い相関を示していることが判った。TiCl3 (AA型)-AlEt3, TiCl3 (AA型)-AlEt2Cl ...
Ichiro Okura, Yoko Sendoda, Tominaga Keii   +2 more
openalex   +3 more sources

Immobilizing metallocene by solid polymethylaluminoxane “sMAO” for slurry-phase ethylene-1-hexene copolymerization [PDF]

MATEC Web of Conferences, 2022
In the field of olefin catalytic polymerization, metallocene catalysts show higher activity than traditional Ziegler-Natta catalysts. In this study, benzoic acid catalyzed the controlled hydrolysis of trimethylaluminum (TMA) to methylaluminoxane (MAO ...
Wu Chaofan, Ge Tengjie, Jiang Zeyu, Jiang Yanfeng, Zhang Qian, Li Jian   +5 more
doaj   +1 more source

The Use of Electron Donors to Increase Stereospecificity in Ziegler-Natta Propylene Polymerization [PDF]

علوم و تکنولوژی پلیمر, 2016
Different chemical components in traditional Ziegler–Natta catalytic system include: (1) titanium and vanadium containing compounds, mostly TiCl4, as an active centre, (2) trialkylaluminium-based Lewis acid compounds, especially triethylaluminium, as ...
Farshid Nouri-Ahangarani, Naeimeh Bahri-Laleh, Mehdi Nekoomanesh-Haghighi   +2 more
doaj   +1 more source

Active site nature of magnesium dichloride-supported titanocene catalysts in olefin polymerization [PDF]

Polyolefins Journal, 2015
Heterogeneous Ziegler-Natta and homogeneous metallocene catalysts exhibit greatly different active sitenature in olefin polymerization. In our previous study, it was reported that MgCl2-supported titanocenecatalysts can generate both Ziegler-Natta-type ...
Toshiaki Taniike, Keisuke Goto, Minoru Terano   +2 more
doaj   +1 more source

A Study on the Effect of Catalyst Types on Microstructure of Ethylene/1-Hexene Copolymer by Thermal Fractionation [PDF]

علوم و تکنولوژی پلیمر, 2015
Olefinic copolymers of ethylene/1-hexene were synthesized by three main types of supported catalysts, including Philips, Ziegler-Natta and metallocene catalysts, and the specific microstructural features delivered by each class of the catalysts were ...
Seyed Mohammad Mehdi Mortazavi
doaj   +1 more source

A Mathematical Model for Investigating the Effect of Reaction Temperature and Hydrogen Amount on the Catalyst Yield during Propylene Polymerization [PDF]

Kemija u Industriji, 2019
In this study, the effect of reaction temperature and hydrogen amount, as the most effective process variables on the Ziegler-Natta catalysts yield during propylene polymerization, was investigated with the aid of a validated mathematical model.
Gholam Hossain Varshouee, Amir Heydarinasab, Ali Vaziri, Seyed Mehdi Ghafelebashi Zarand   +3 more
doaj   +1 more source