Oxidation reaction of high molecular weight dicarboxylic acids in sub- and supercritical water

2008 ◽  
Vol 44 (3) ◽  
pp. 331-340 ◽  
Author(s):  
Fangming Jin ◽  
Jianxun Cao ◽  
Atsushi Kishita ◽  
Heiji Enomoto ◽  
Takehiko Moriya
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Supercritical Water ◽  
Oxidation Reaction ◽  
Dicarboxylic Acids

scholarly journals New 1,2,3-Triazole Containing PolyestersviaClick Step-Growth Polymerization and Nanoparticles Made of Them

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tengiz Kantaria ◽  
Temur Kantaria ◽  
Giorgi Titvinidze ◽  
Giuli Otinashvili ◽  
Nino Kupatadze ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sodium Azide ◽  
Dicarboxylic Acids ◽  
Solution Concentration ◽  
One Pot ◽  
Bromoacetic Acid ◽  
Aliphatic Polyesters ◽  
Step Growth ◽  
Step Growth Polymerization

High-molecular-weight AA-BB-type aliphatic polyesters were synthesizedviaCu(I)-catalyzed click step-growth polymerization (SGP) following a new synthetic strategy. The synthesis was performed between diyne and diazide monomers in an organic solvent as one pot process using three components and two stages. The dipropargyl esters of dicarboxylic acids (component 1) were used as diyne monomers, di-(bromoacetic acid)-alkylene diesters (component 2) were used as precursors of diazide monomers, and sodium azide (component 3) was used for generating diazide monomers. The SGP was carried out in two steps: at Step  1 dibromoacetates interacted with two moles of sodium azide resulting in diazide monomers which interacted in situ with diyne monomers at Step  2 in the presence of Cu(I) catalyst. A systematic study was done for optimizing the multiparameter click SGP in terms of the solvent, duration of both Step  1 and Step  2, solution concentration, catalyst concentration, catalyst and catalyst activator (ligand) nature, catalyst/ligand mole ratio, and temperature of both steps of the click SGP. As a result, high-molecular-weight (MWup to 74 kDa) elastic film-forming click polyesters were obtained. The new polymers were found suitable for fabricating biodegradable nanoparticles, which are promising as drug delivery containers in nanotherapy.

Preparation of high molecular weight compounds on the basis of cyclic imides and diimides of dicarboxylic acids

2007 ◽  
Vol 16 (3) ◽  
pp. 1631-1646 ◽  
Author(s):  
T. V. Sheremeteva ◽  
G. N. Larina ◽  
M. G. Zhenevskaya ◽  
V. A. Gusinskaya
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Dicarboxylic Acids ◽  
Cyclic Imides

Concrete Superplasticizer Prepared from Catalytic Oxidation of Lignosulfonate

2012 ◽  
Vol 424-425 ◽  
pp. 1088-1092 ◽  
Author(s):  
Zhe Wang ◽  
Jing Wen Xue ◽  
Ji Shi Zhang ◽  
Wen Xia Liu
Keyword(s):  
Molecular Weight ◽  
Catalytic Oxidation ◽  
High Molecular Weight ◽  
Cement Paste ◽  
Oxidation Reaction ◽  
Ph Value ◽  
Oxidative Degradation ◽  
Main Reaction ◽  
Sulfonic Group

Bamboo lignosulfonate was modified under the role of H2O2 and catalyst in order to improve the dispersing property of lignosulfonate. Results show that the amount of H2O2 and pH value have strong influences on characteristics of lignosulfonate. Cement paste fluidity of lignosulfonate modified at pH5 and 11% H2O2 is 178mm, which is 68% higher than that of unmodified lignosulfonate. Both of oxidative degradation and condensation occur during catalytic oxidation reaction, but oxidation is the main reaction when high amount of H2O2 is applied. The structure of lignosulfonate has some relationship to water reducing property. High molecular weight, high carboxylic content and proper sulfonic group content are the main reasons that enhance water reducing property of lignosulfonate.

scholarly journals A new series of long-chain dicarboxylic acids with vicinal dimethyl branching found as major components of the lipids of Butyrivibrio spp

1979 ◽  
Vol 183 (3) ◽  
pp. 691-700 ◽  
Author(s):  
R A Klein ◽  
G P Hazlewood ◽  
P Kemp ◽  
R M C Dawson
Keyword(s):  
Molecular Weight ◽  
Fatty Acid ◽  
High Molecular Weight ◽  
Mass Spectroscopy ◽  
Major Part ◽  
Dicarboxylic Acids ◽  
Synthetic Compounds ◽  
High Molecular Weight Component ◽  
Complex Lipids ◽  
Long Chain

1. Some members of the genus Butyrivibrio, including a general fatty acid auxotroph (strain S2), contain as a major part of their complex lipids a high-molecular-weight component that is probably formed by the union of two fatty acid chains [Hazlewood & Dawson (1979) J. Gen. Microbiol. 112, 15–27]. 2. Proton and 13C n.m.r. and i.r. and mass spectroscopy were used to examine a homologous series of these moieties and, in addition, the hydrocarbon derivative of one homologue and several synthetic compounds. 3. The results indicate that the high-molecular-weight components are a series of long-chain dicarboxylic acids containing vicinal dimethyl branching, located near the centre of the chain.

Microtubule motors and other maps

1990 ◽  
Vol 48 (3) ◽  
pp. 1-1
Author(s):  
Richard B. Vallee
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cytoplasmic Dynein ◽  
Organelle Transport ◽  
Structural Components ◽  
Microtubule Associated Proteins ◽  
Microtubule Motors ◽  
Associated Proteins ◽  
The Subject ◽  
Intracellular Motility

Microtubules are involved in a number of forms of intracellular motility, including mitosis and bidirectional organelle transport. Purified microtubules from brain and other sources contain tubulin and a diversity of microtubule associated proteins (MAPs). Some of the high molecular weight MAPs - MAP 1A, 1B, 2A, and 2B - are long, fibrous molecules that serve as structural components of the cytamatrix. Three MAPs have recently been identified that show microtubule activated ATPase activity and produce force in association with microtubules. These proteins - kinesin, cytoplasmic dynein, and dynamin - are referred to as cytoplasmic motors. The latter two will be the subject of this talk.Cytoplasmic dynein was first identified as one of the high molecular weight brain MAPs, MAP 1C. It was determined to be structurally equivalent to ciliary and flagellar dynein, and to produce force toward the minus ends of microtubules, opposite to kinesin.

Sign in / Sign up

Export Citation Format

Share Document