Ethylene Polymerization by a New Zirconium Complex

2011 ◽  
Vol 214 ◽  
pp. 699-703
Author(s):  
Zheng Zai Cheng ◽  
Yu Jing Nie ◽  
Xiao Chao Yan ◽  
Rui Lei ◽  
Su Su Lin
Keyword(s):  
Molecular Weight ◽  
Reaction Temperature ◽  
Ethylene Polymerization ◽  
Average Molecular Weight ◽  
Zirconium Complex ◽  
Melting Points ◽  
Ligand Complex ◽  
Dichloromethane Solution ◽  
Gel Permeation ◽  
Very High

Novel zirconium complex C2 has been prepared by treatment of the ligand complex C1 with ZrCl4•2THF in dichloromethane solution. The complex C1 and C2 were characterized by 1H-NMR and IR. Activated by MAO, Complex C2 displays very high activity for ethylene polymerization under the reaction temperature of 30～80°C and the viscosity-average molecular weight of polyethylene is more than 3.50×104 when reaction temperature is no more than 60°C.The molecular-weight distribution measured by gel permeation reached 2.3.High melting points measured by DSC indicates that the polyethylene produced by complex C2 is high linearity and high crystallinity.

Prepare of Novel Zirconium Complex and Catalytic Performance for Ethylene Polymerization

2011 ◽  
Vol 179-180 ◽  
pp. 1091-1095 ◽  
Author(s):  
Zheng Zai Cheng ◽  
Yu Jing Nie ◽  
Xiao Chao Yan ◽  
Rui Lei ◽  
Su Su Lin
Keyword(s):  
Molecular Weight ◽  
Reaction Temperature ◽  
Ethylene Polymerization ◽  
Average Molecular Weight ◽  
Catalytic Performance ◽  
Zirconium Complex ◽  
Melting Points ◽  
Ligand Complex ◽  
Dichloromethane Solution ◽  
Very High

Novel zirconium complex 2 has been prepared by treatment of the ligand complex 1 with ZrCl4•2THF in dichloromethane solution. The complex 1 and 2 were characterized by 1H-NMR and IR. Activated by MAO, Complex 2 displays very high activity for ethylene polymerization under the reaction temperature of 40～80 °C and the viscosity-average molecular weight of polyethylene is more than 3.0×104 when reaction temperature is no more than 60°C.The molecular-weight distribution measured by gel permeation reached 2.50.High melting points measured by DSC indicates that the polyethylene produced by complex 2 is high linearity and high crystallinity.

Polymerization of Methyl Methacrylate with a Novel Titanium Complex

2011 ◽  
Vol 179-180 ◽  
pp. 1203-1207
Author(s):  
Zheng Zai Cheng ◽  
Yu Jing Nie ◽  
Xiao Chao Yan ◽  
Rui Lei ◽  
Su Su Lin
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Ligand Complex ◽  
Dichloromethane Solution ◽  
Titanium Complex ◽  
Methyl Methacrylate Polymerization ◽  
Gel Permeation ◽  
Very High

Novel titanium complex [2-O-(5- NO2)C6H3CH=N[(C6H4) –2-O ]]2TiCl2 (1) has been prepared by treatment of the ligand complex 1a with TiCl4•2THF in dichloromethane solution. The complex 1a and 1 were characterized by 1H-NMR . Activated by MAO, Complex 1 displayed very high activity for methyl methacrylate polymerization and the viscosity-average molecular weight of PMMA is more than 35×104 at 60°C.The molecular-weight distribution of PMMA measured by gel permeation chromatography (GPC) is narrow.

Novel Iron(II) Complex as Single-Site Catalysts for Ethylene Polymerization

2011 ◽  
Vol 239-242 ◽  
pp. 3314-3318
Author(s):  
Zheng Zai Cheng ◽  
Ye Cong ◽  
Xiao Chao Yan ◽  
Yu Jing Nie ◽  
Su Su Lin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Activity ◽  
Weight Distribution ◽  
Ethylene Polymerization ◽  
High Melting ◽  
Melting Points ◽  
H Nmr ◽  
Gel Permeation ◽  
Single Site Catalysts ◽  
Very High

Novel iron (II) complex C2has been prepared by treatment of the ligand C1with FeCl2in THF solution. The complex C1was characterized by MSand1H-NMR and complex C2was characterized by MSand element analyze. Activated by MAO, complex 2 exhibites very high activity and produces high molecular weight polyethylene. The molecular weight distribution measured by gel permeation reached 2.1 to 2.4. the GPC profile of PE obtained and High melting points measured by DSC indicates indicates that the polyethylene produced by complex C2is high linearity and high crystallinity.

Alternating poly(ester amide)s from glutaric anhydride and α,ω-aminoalcohols: synthesis and thermal properties

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Thomas Fey ◽  
Helmut Keul ◽  
Hartwig Höcker
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Homologous Series ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Melting Points ◽  
Glutaric Anhydride ◽  
H Nmr ◽  
Activating Agent ◽  
Dimethylformamide Solution

Abstract Alternating poly(ester amide)s 6a - e were prepared by polycondensation of α-carboxyl-ω-hydroxyamides 3a - e which were obtained by aminolysis of glutaric anhydride (1) and α,ω-aminoalcohols, H2N-(CH2)x-OH (x = 2 - 6) 2a - e. The polycondensation was performed in dimethylformamide solution using a carbodiimide as activating agent, or in bulk with Bu2Sn(OMe)2, Ti(OBu)4 and Sn(octoate)2 as a catalyst. For the polycondensation in bulk, the influence of catalyst and of temperature on the number-average molecular weight was studied. 1H NMR analyses of the poly(ester amide)s clearly show the alternating microstructure. The poly(ester amide)s from glutaric anhydride and the homologous series of α,ω-aminoalcohols are semicrystalline materials; their melting points show the odd/even effect observed for other poly(ester amide)s.

Randomly Branched Polymers. II. Computer Analysis of Gel-Permeation Chromatograms

1976 ◽  
Vol 49 (5) ◽  
pp. 1290-1304
Author(s):  
M. Kurata ◽  
H. Okamoto ◽  
M. Iwama ◽  
M. Abe ◽  
T. Homma
Keyword(s):  
Molecular Weight ◽  
Weight Distribution ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Computer Method ◽  
Branched Polymers ◽  
Branch Points ◽  
Weight Average Molecular Weight ◽  
Degree Of Branching ◽  
Gel Permeation

Abstract An iterative computer method was proposed for estimating the degree of branching and molecular weight distribution simultaneously from a pair of measurements on intrinsic viscosity and gel-permeation chromatography. The validity of the method as applied to randomly branched polymers was tested by using both fractionated and unfractionated samples of branched polystyrenes. It was experimentally concluded that the average number of branch points per unit molecular weight, λ, can be determined by this method with an accuracy of about 15%, and the weight-average molecular weight with accuracy of about 10%.

Study on Synthesis and Properties of Phenols Polymer Syntan Catalyzed by Enzyme

2011 ◽  
Vol 138-139 ◽  
pp. 1072-1077
Author(s):  
Sheng Hua Lv ◽  
Rui Gong ◽  
Yan Fen Ma
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Structure And Properties ◽  
Monomer Composition ◽  
Gel Permeation

A phenolic copolymer was synthesized from resorcinol (RSC) and 3,5-dihydroxy benzoic acid (DBA) using horseradish peroxidase (HRP)/H2O2 as the radical copolymerization’s initiateor. It was discussed that the effects of monomer composition on the properties of the copolymer. The best molar ratio was 1:1. The structure and properties of the copolymer was characterized by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (HNMR), Molecular weight (MW) was determined by gel permeation chromatography (GPC). The result shows that the average molecular weight of the copolymer is about 40000. The effect of dosage of HRP on the properties of the copolymer was investigated. And the mechanism of polymerization of RSC and DBA was advanced. The copolymer was used as tanning agent, applied results show that it has excellent retanning properties. It was realized the applicatiom of HRP on the phenols syntan.

Synthesis of Polycarboxylate: Its Characterization and Application as a Superplasticizer in Concrete

2012 ◽  
Vol 204-208 ◽  
pp. 4181-4186
Author(s):  
Xiang Yin Mo ◽  
Xian San Feng ◽  
Chen Jie Yu ◽  
Ying Jie Jing
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Cement Paste ◽  
Reaction Temperature ◽  
Methyl Acrylate ◽  
Average Molecular Weight ◽  
Monomethyl Ether ◽  
Noticeable Effect ◽  
Flow Test ◽  
Weight Effect

Polycarboxylate was synthesized by using polyethylene glycol monomethyl ether methyl-acrylate (PEG16), methylacrylamide sodium (MAS), methacrylic acid (MAA), methyl acrylate (MA), acryl amide (AM), and sodium persulfate (SPS) and evaluated as a superplasticizer for cement particles. The formulation of the superplasticizer: n (PEG16): n (MAS): n (MAA): n (MA): n (AM) =10:18:20:37:20, and the content of the SPS was 1.2wt% of all the monomers and optimized reaction conditions (80°C, 6h) were obtained via orthogonal test and single factor experiments. The water reducing effect of the synthesized copolymers was studied in terms of reaction temperature, reaction time and PEG side chain length. In this study, flow test of cement paste measurements were performed to compare the molecular weight effect on fluidity of the copolymers. It was observed that the reaction temperature had a noticeable effect on the molecular weight of the PEG-grafted samples thus causing a significant effect on fluidity. The polycarboxylate synthesized at about 80°C has given the highest fluidity result. In addition, the reaction time 6~7 hrs was identified for the best. Furthermore, copolymers with mPEG side chains with a degree of 16 gave the highest fluidity and viscosity average molecular weight value. The initial fluidity of the cement paste containing the prepared superplasticizer (1wt%, w(water)/w(cement)=(0.29)) was 316 mm.

Sign in / Sign up

Export Citation Format

Share Document