Ethylene Polymerization by Phenyl Sulfide Bridged Dinuclear Zirconocene Complex/MAO

2011 ◽  
Vol 181-182 ◽  
pp. 809-813
Author(s):  
Yu Jing Nie ◽  
Ming Yang
Keyword(s):  
Catalytic Activity ◽  
Ethylene Polymerization ◽  
Catalyst Concentration ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Phenyl Sulfide ◽  
Concentration Time ◽  
Cyclopentadienyl Ligand ◽  
Broad Molecular Weight Distribution ◽  
Higher Temperature

The phenyl sulfide bridged Zirconocene complex [(C5H5)Cl2ZrC5H4CH2(C6H4-p)]2S has been synthesized by treating the dilithium salts of the phenyl sulfide bridged cyclopentadienyl ligand with two equivalents of C5H5ZrCl3(DME) and characterized by 1HMNR and elemental analysis. Homogenous ethylene polymerization by this complex has been conducted systematically in the presence of methylaluminoxane (MAO). The influence of the molar ratio [MAO]/[Cat], the catalyst concentration, time and temperature have been studied in detail. The highest catalytic activity of 1 is up to 13.78×105 g PE/mol•Cat•h. Higher temperature is favorable for increasing the catalytic activity for 1. High temperature gel permeation chromatography (HT-GPC) proves the production of polyethylene with a broad molecular weight distribution (MWD), which is reached 6.02.

Ethylene Polymerization by Thioether Bridged Dinuclear Zirconocene Complex

2011 ◽  
Vol 213 ◽  
pp. 374-377 ◽  
Author(s):  
Yu Jing Nie ◽  
Ming Yang
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Ethylene Polymerization ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
High Concentration ◽  
Concentration Time ◽  
Cyclopentadienyl Ligand ◽  
Broad Molecular Weight Distribution ◽  
Higher Temperature

The thioether bridged Zirconocene complex [(C5H5)Cl2ZrC5H4CH2CH2]2S has been synthesized by treating the dilithium salts of the thioether bridged cyclopentadienyl ligand with two equivalents of C5H5ZrCl3(DME) and characterized by 1HMNR and elemental analysis. Homogenous ethylene polymerization by this complex has been conducted systematically in the presence of methylaluminoxane (MAO). The influence of the molar ratio [MAO]/[Cat], the catalyst concentration, time and temperature have been studied in detail. The catalytic activity of 1 is 6.46×105 g PE/mol•Cat•h. Higher temperature is favorable for increasing the catalytic activity for 1. A high concentration of the catalysts drops the catalytic activity as well as the molecular weight of polyethylene for the complex. High temperature gel permeation chromatography (HT-GPC) proves the production of polyethylene with a broad molecular weight distribution (MWD).

Ethylene Polymerization by Phenyl Sulfide Bridged Dinuclear Titanocene Complex/MAO

2011 ◽  
Vol 181-182 ◽  
pp. 804-808
Author(s):  
Yu Jing Nie ◽  
Ming Yang
Keyword(s):  
Catalytic Activity ◽  
Ethylene Polymerization ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Polymerization Temperature ◽  
Phenyl Sulfide ◽  
Highly Active ◽  
Concentration Time ◽  
Cyclopentadienyl Ligand ◽  
Broad Molecular Weight Distribution

The phenyl sulfide bridged metallocene complex [(C5H5)Cl2TiC5H4CH2(C6H4-p)]2S has been synthesized by treating the dilithium salts of the phenyl sulfide bridged cyclopentadienyl ligand with two equivalents of C5H5TiCl3 and characterized by 1HMNR and elemental analysis. After activation with methylaluminoxane (MAO), the complex was highly active catalysts for homogeneous ethylene polymerization in toluene. The influence of the molar ratio [MAO]/[Cat], the catalyst concentration, time and temperature have been studied systematically. The highest catalytic activity of 1 is up to 8.30×105 g PE/mol•Cat•h. Rising the polymerization temperature decreases the catalytic activity for 1. High temperature gel permeation chromatography (HT-GPC) proves the production of polyethylene with a broad molecular weight distribution (MWD), which is reached 10.11.

Ethylene Polymerization by Thioether Bridged Dinuclear Titanocene Complex

2011 ◽  
Vol 213 ◽  
pp. 354-357 ◽  
Author(s):  
Yu Jing Nie ◽  
Ming Yang
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Ethylene Polymerization ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Polymerization Temperature ◽  
High Concentration ◽  
Highly Active ◽  
Cyclopentadienyl Ligand ◽  
Broad Molecular Weight Distribution

The thioether bridged metallocene complex [(C5H5)Cl2TiC5H4CH2CH2]2S has been synthesized by treating the dilithium salts of the thioether bridged cyclopentadienyl ligand with two equivalents of C5H5TiCl3 and characterized by 1HMNR and elemental analysis. After activation with methylaluminoxane (MAO), the complex was highly active catalysts for homogeneous ethylene polymerization in toluene. The influence of the molar ratio [MAO]/[Cat], the catalyst concentration, time and temperature have been studied systematically. The catalytic activity of 1 is 3.63×105 g PE/mol•Cat•h. Rising the polymerization temperature decreases the catalytic activity for 1. A high concentration of the catalysts drops the catalytic activity as well as the molecular weight of polyethylene for the complex. High temperature gel permeation chromatography (HT-GPC) proves the production of polyethylene with a broad molecular weight distribution (MWD).

scholarly journals BIODIESEL FROM FAT OF TRA CATFISH VIA KOH/γ-Al2O3 CATALYST USING ULTRASONIC MIXING

2010 ◽  
Vol 13 (2) ◽  
pp. 72-80
Author(s):  
Huong Thi Thanh Le ◽  
Ngan Phuong Huynh ◽  
Tan Minh Phan ◽  
Hoa Thi Viet Tran
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Energy Input ◽  
Catalyst Concentration ◽  
Low Frequency ◽  
Molar Ratio ◽  
Concentration Time ◽  
Heterogenous Catalyst ◽  
Al2o3 Catalyst ◽  
Reaction Wave

In the present study, the methanolysis of tra fat using KOH/γ-Al2O3 as heterogenous catalyst was performed with the help of low frequency ultrasonic processor (20 kHz). The main object of this study was to investigate the influences of parameters like methanol to fat molar ratio, catalyst concentration, time and temperature of reaction, wave amplitudes, and energy input on the yield of biodiesel. Moreover, this research also examined the influences of ultrasonic wave on the fatty acid composition and the properties of KOH/γ-Al2O3 catalyst.

Preparation of Polyethylene with Vanadium/Titanium Bi-Metal Ziegler-Natta Catalysts

2014 ◽  
Vol 665 ◽  
pp. 335-338
Author(s):  
Tao Jiang ◽  
Xiang Lu Gao
Keyword(s):  
Ethylene Polymerization ◽  
Bimetallic Catalyst ◽  
Gel Permeation Chromatography ◽  
Catalyst System ◽  
Molar Ratio ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Vanadium Titanium ◽  
Ziegler Natta Catalysts ◽  
C Nmr

The catalyst with magnesium chloride supported vanadium/titanium bimetallic Ziegler-Natta catalysts has been prepared. The effects of V/Ti molar ratio and dosage of α-olefin on catalytic activity of ethylene polymerization were investigated. Gel permeation chromatography (GPC),13C-NMR spectra and differential scanning calorimetry (DSC) analysis were performed to characterize the polymers. The results indicated that the bimetallic catalyst system produced PE with broad and bimodal MWD.

Metathesis Polymerization of Phenylacetylene by Tungsten Aryloxo Complexes

1995 ◽  
Vol 60 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Hynek Balcar ◽  
Jan Sedláček ◽  
Marta Pacovská ◽  
Vratislav Blechta
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Induction Period ◽  
Average Molecular Weight ◽  
Molar Fraction ◽  
Molar Ratio ◽  
Weight Average Molecular Weight ◽  
Polymer Yield ◽  
Positive Effect ◽  
Ligand Addition

Catalytic activity of the tungsten aryloxo complexes WCl5(OAr) and WOCl3(OAr), where Ar = 4-t-C4H9C6H4, 2,6-(t-C4H9)2C6H3, 2,6-Cl2C6H3, 2,4,6-Cl3C6H2, and 2,4,6-Br3C6H2 in polymerization of phenylacetylene (20 °C, monomer to catalyst molar ratio = 1 000) was studied. The activity of WCl5(OAr) as unicomponent catalysts increases with increasing electron withdrawing character of the -OAr ligand. Addition of two equivalents of organotin cocatalysts (Me4Sn, Bu4Sn, Ph4Sn, Bu3SnH) to WCl5(O-C6H2Cl3-2,4 ,6) has only slight positive effect (slightly higher polymer yield and/or molecular weight of poly(phenylacetylene)s was achieved). However, in the case of WOCl3(O-C6H3Cl2-2, 6) catalyst, it enhances the activity considerably by eliminating the induction period. Poly(phenylacetylene)s prepared with the catalysts studied have weight-average molecular weight ranging from 100 000 to 200 000. They are trans-prevailing and have relatively low molar fraction of monomer units comprised in cyclohexadiene sequences (about 6%).

scholarly journals One-step synthesis of nitrogen-grafted copper-gallic acid for enhanced methylene blue removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shella Permatasari Santoso ◽  
Vania Bundjaja ◽  
Artik Elisa Angkawijaya ◽  
Chintya Gunarto ◽  
Alchris Woo Go ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Gallic Acid ◽  
Synthesis Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
One Step ◽  
Detailed Assessment ◽  
Higher Temperature

AbstractNitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.

Optimization of biodiesel synthesis under simultaneous ultrasound-microwave irradiation using response surface methodology (RSM)

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Seyed Mohammad Safieddin Ardebili ◽  
Teymor Tavakoli Hashjin ◽  
Barat Ghobadian ◽  
Gholamhasan Najafi ◽  
Stefano Mantegna ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Microwave Irradiation ◽  
Response Surface ◽  
Palm Oil ◽  
Catalyst Concentration ◽  
Irradiation Time ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Biodiesel Synthesis

AbstractThis work investigates the effect of simultaneous ultrasound-microwave irradiation on palm oil transesterification and uncovers optimal operating conditions. Response surface methodology (RSM) has been used to analyze the influence of reaction conditions, including methanol/palm oil molar ratio, catalyst concentration, reaction temperature and irradiation time on biodiesel yield. RSM analyses indicate 136 s and 129 s as the optimal sonication and microwave irradiation times, respectively. Optimized parameters for full conversion (97.53%) are 1.09% catalyst concentration and a 7:3.1 methanol/oil molar ratio at 58.4°C. Simultaneous ultrasound-microwave irradiation dramatically accelerates the palm oil transesterification reaction. Pure biodiesel was obtained after only 2.2 min while the conventional method requires about 1 h.

The Influence of Fe/Al Molar Ratio on Microreactor-Based Catalyst Preparation and Carbon Nanotube Preparation

2021 ◽  
Vol 1036 ◽  
pp. 130-136
Author(s):  
Ting Qun Tan ◽  
Lei Geng ◽  
Yan Lin ◽  
Yan He
Keyword(s):  
Carbon Nanotubes ◽  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Small Diameter ◽  
High Specific Surface Area ◽  
Detection Methods ◽  
Molar Ratio ◽  
High Catalytic Activity

In order to prepare carbon nanotubes with high specific surface area, small diameter, low resistivity, high purity and high catalytic activity, the Fe-Mo/Al2O3 catalyst was prepared based on the microreactor. The influence of different Fe/Al molar ratios on the catalyst and the carbon nanotubes prepared was studied through BET, SEM, TEM and other detection methods. Studies have shown that the pore structure of the catalyst is dominated by slit pores at a lower Fe/Al molar ratio. The catalytic activity is the highest when the Fe/Al molar ratio is 1:1, reaching 74.1%. When the Fe/Al molar ratio is 1:2, the catalyst has a higher specific surface area, the maximum pore size is 8.63 nm, and the four-probe resistivity and ash content of the corresponding carbon nanotubes are the lowest. The higher the proportion of aluminum, the higher the specific surface area of the catalyst and the carbon nanotubes, and the finer the diameter of the carbon nanotubes, which gradually tends to relax. The results show that when the Fe/Al molar ratio is 1:2, although the catalytic activity of the catalyst is not the highest, the carbon nanotubes prepared have the best performance.

Application of Deep Eutectic Solvent (DES) as a Reaction Media for the Esterification of Acrylic Acid with n-Butanol

2015 ◽  
Vol 13 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Emine Sert
Keyword(s):  
Catalytic Activity ◽  
Acrylic Acid ◽  
Batch Reactor ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Toluene Sulfonic Acid ◽  
Effects Of Temperature ◽  
Reaction Media

Abstract Within the framework of green chemistry, catalysts should be met different criteria such as biodegradability, recyclability, flammability, non-toxicity and low price. Acidic deep eutectic solvent (DES) have been synthesized for this purpose, by mixing para-toluene sulfonic acid and choline chloride. The catalytic activity of DES was studied in the esterification of acrylic acid with n-butanol. The usage of DES as catalyst is simple, safe and cheap. The effects of temperature, catalyst loading, n-butanol/acrylic acid molar ratio on the conversion of acrylic acid were performed. The batch reactor experiments were carried out at temperatures of 338, 348, 358 and 368 K, molar ratio of butanol to acrylic acid of 1, 2,3 and catalyst loading of 10, 15, 20 and 90 g/L. 90.2% of acrylic acid conversion was achieved at a temperature of 358 K and catalyst loading of 20 g/L. Reusability of DES was investigated. Reusability and catalytic activity makes DES efficient as catalyst.

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