scholarly journals Polymerization of Phenylacetylene-Based Monodendrons with Alkoxy Peripheral Groups and Oxygen/Nitrogen Permeation Behavior of Their Membranes

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Kaneko ◽  
Kazuaki Sato ◽  
Yoshihiko Uchiya ◽  
Masahiro Teraguchi ◽  
Toshiki Aoki
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Focal Point ◽  
Rhodium Catalyst ◽  
Terminal Acetylene ◽  
Permselective Membrane

Monodendron monomers with alkoxy peripheral groups were synthesized, and the focal point of monodendrons, terminal acetylene, was polymerized with rhodium catalyst to yield corresponding polydendrons with a high molecular weight. The polydendrons were soluble in common organic solvents and readily formed membranes. Oxygen permselectivity was improved in the polydendrons with a space-persistent dendritic crowd. It was found that the well-defined dendritic and rod-like structure of the polydendrons was useful for permselective membrane.

scholarly journals Isolation of High-Molecular-Weight DNA Using Organic Solvents

2017 ◽  
Vol 2017 (4) ◽  
pp. pdb.prot093450 ◽  
Author(s):  
Michael R. Green ◽  
Joseph Sambrook
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
High Molecular Weight Dna

Synthesis and Properties of a High-Molecular-Weight Polyimide Based on 4, 4'-(hexafluoroisopropylidene) Diphthalic Anhydride

2012 ◽  
Vol 550-553 ◽  
pp. 742-746
Author(s):  
Hui Wen Wu ◽  
Hua Li ◽  
He Zhou Liu
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Membrane Separation ◽  
Amic Acid ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Synthesis Parameters ◽  
Soluble Polyimide

A soluble polyimide with high molecular weight was synthesized from 4, 4'-(hexafluoroiso propylidene) diphthalic anhydride (6FDA) and 2, 2’-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (BAPAF) via two-step polycondesation procedure involving the preparation of poly(amic acid) (PAA) followed by chemical imidization. Effect of synthesis parameters on polyimide molecular weight involving material ratio, imidization temperature and imidization catalyst were studied. Synthesized PI was analyzed with respect to their molecular weights, chemical structures and solubility through GPC, FTIR, XRD and solubility tests respectively. The results showed that a high-molecular-weight PI was successfully synthesized from 4, 4'-(hexafluoroisopropylidene) diphthalic anhydride and 2, 2’-bis (3-amino-4-hydroxyphenyl) hexafluoropropane with imidization at 80°C for 3h, material ratio of n(BAPAF):n(6FDA) equal to 1:1 and catalyst of n(triethylamine):n (pyridine) less than1:3. The obtained PI showed excellent solubility in polar aprotic organic solvents such as NMP, DMAc, DMSO, THF and Acetone. Poly(6FDA-BAPAF) PI, with high molecular weight and excellent solubility, which was synthesized under lower imidization temperature that was equal to 80°C,could be easily obtained and convenient to process, thus it is a potential material for membrane separation.

scholarly journals The Origin of Chlororganic Compounds in Crude Oil and Oil Fractions

2020 ◽  
Vol 131 (6) ◽  
pp. 3-10
Author(s):  
V. K. Miller ◽  
◽  
D. V. Marochkin ◽  
Yu. G. Noskov ◽  
G. A. Korneeva ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydrochloric Acid ◽  
Crude Oil ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Oil Production ◽  
Organochlorine Compounds ◽  
Oil Fractions ◽  
Acid Acid

In this review, published information on the nature and molecular compositions of organochlorine compounds (OCCs), which are found in crude oil and in its refined products, is systematized. The native and added OCCs are reviewed. The formers are concentrated predominantly in high molecular weight resinous-asphaltene substances of crude oil, the latter’s, referred to as light organochlorine compounds, are present in the gasoline fractions. The following chemicals that are used for oil production are regarded as possible sources of OCCs: inhibited hydrochloric acid, acid compounds; organic solvents of asphalt-resin-paraffin deposits, organic solvents served for oil production stimulation, and possible products of a mutual solvent chlorination with hydrochloric acid.

scholarly journals Hyperbranched polydendrons: a new controlled macromolecular architecture with self-assembly in water and organic solvents

2014 ◽  
Vol 5 (5) ◽  
pp. 1844-1853 ◽  
Author(s):  
Fiona L. Hatton ◽  
Pierre Chambon ◽  
Tom O. McDonald ◽  
Andrew Owen ◽  
Steven P. Rannard
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Self Assembly ◽  
Hybrid Copolymer ◽  
Macromolecular Architecture ◽  
Very High

A new macromolecular architecture comprising multiple linear-dendritic hybrid copolymer sub-units is presented – hyperbranched polydendrons. The materials are very high molecular weight and disperse but undergo extremely uniform self-assembly behaviour.

Well-defined phosphino-phenolate neutral nickel(ii) catalysts for efficient (co)polymerization of norbornene and ethylene

2015 ◽  
Vol 44 (16) ◽  
pp. 7382-7394 ◽  
Author(s):  
Yan-Ping Zhang ◽  
Wei-Wei Li ◽  
Bai-Xiang Li ◽  
Hong-Liang Mu ◽  
Yue-Sheng Li
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Nickel Catalysts ◽  
Good Solubility ◽  
Highly Efficient

With B(C6F5)3as a singular cocatalyst, a series of phosphino-phenolate neutral nickel catalysts were found to be highly efficient for norbornene (co)polymerization. High molecular weight (co)polymers with good solubility in common organic solvents were obtained.

scholarly journals Chemoselective Lewis pair polymerization of renewable multivinyl-functionalized γ-butyrolactones

2017 ◽  
Vol 375 (2101) ◽  
pp. 20170003 ◽  
Author(s):  
Ravikumar R. Gowda ◽  
Eugene Y.-X. Chen
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Lewis Acid ◽  
Room Temperature ◽  
Lewis Base ◽  
Functionalized Polymers ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Multivinyl-functionalized γ-butyrolactones, γ-vinyl-γ-methyl-α-methylene-γ-butyrolactone ( γ VMMBL) and γ-allyl-γ-methyl-α-methylene-γ-butyrolactone ( γ AMMBL), have been synthesized from biorenewable ethyl levulinate and effectively polymerized by Lewis pairs consisting of an organic N -heterocyclic carbene Lewis base and a strong organo-Lewis acid E(C 6 F 5 ) 3 (E = Al, B). This Lewis pair polymerization is quantitatively chemoselective, proceeds exclusively via polyaddition across the conjugated α-methylene double bond without participation of the γ-vinyl or γ-allyl double bond, and produces high-molecular-weight functionalized polymers with unimodal molecular-weight distributions. The Al-based Lewis pair produces a polymer with approximately 5.5 times higher molecular weight than that produced by the B-based Lewis pair. The resulting vinyl-functionalized polymers are soluble in common organic solvents and stable at room temperature, and can be thermally cured into crosslinked materials. This article is part of the themed issue ‘Frustrated Lewis pair chemistry’.

scholarly journals A rapid and simple method for the isolation of high molecular weight cellular and chromosome-specific DNA in solution without the use of organic solvents

1987 ◽  
Vol 15 (2) ◽  
pp. 859-859 ◽  
Author(s):  
J.L. Longmire ◽  
K.L. Albright ◽  
A.K. Lewis ◽  
L.J. Meincke ◽  
C.E. Hildebrand
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Solvents ◽  
Simple Method
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