RAFT Polymerization of Methyl 6-O-Methacryloyl-α-d-glucoside in Homogeneous Aqueous Medium. A Detailed Kinetic Study at the Low Molecular Weight Limit of the Process

2007 ◽  
Vol 40 (17) ◽  
pp. 6082-6093 ◽  
Author(s):  
Luca Albertin ◽  
Neil R. Cameron
Keyword(s):  
Molecular Weight ◽  
Kinetic Study ◽  
Aqueous Medium ◽  
Raft Polymerization ◽  
Low Molecular Weight

scholarly journals Low Molecular Weight pDMAEMA-block-pHEMA Block-Copolymers Synthesized via RAFT-Polymerization: Potential Non-Viral Gene Delivery Agents?

Polymers ◽  
2011 ◽  
Vol 3 (2) ◽  
pp. 693-718 ◽  
Author(s):  
Olga Samsonova ◽  
Christian Pfeiffer ◽  
Markus Hellmund ◽  
Olivia M. Merkel ◽  
Thomas Kissel
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Gene Delivery ◽  
Raft Polymerization ◽  
Viral Gene ◽  
Low Molecular Weight ◽  
Viral Gene Delivery

A Potential New RAFT - Click Reaction or a Cautionary Note on the Use of Diazomethane to Methylate RAFT-synthesized Polymers

2011 ◽  
Vol 64 (4) ◽  
pp. 433 ◽  
Author(s):  
Ming Chen ◽  
Graeme Moad ◽  
Ezio Rizzardo
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Room Temperature ◽  
Click Reaction ◽  
Raft Polymerization ◽  
Dipolar Cycloaddition ◽  
Low Molecular Weight ◽  
Similar Reaction ◽  
Poly Methyl Methacrylate ◽  
End Groups

It has been found that diazomethane undergoes a facile 1,3‐dipolar cycloaddition with both dithiobenzoate RAFT agents and the dithiobenzoate end‐groups of polymers formed by RAFT polymerization. Thus, 2‐cyanoprop‐2‐yl dithiobenzoate on treatment with diazomethane at room temperature provided a mixture of stereoisomeric 1,3‐dithiolanes in near quantitative (>95%) yield. A low‐molecular‐weight RAFT‐synthesized poly(methyl methacrylate) with dithiobenzoate end‐groups underwent similar reaction as indicated by immediate decolourization and a quantitative doubling of molecular weight. Higher‐molecular‐weight poly(methyl methacrylate)s were also rapidly decolourized by diazomethane and provided a product with a bimodal molecular weight distribution. Under similar conditions, the trithiocarbonate group does not react with diazomethane.

Miscibility of Starch and Low Molecular Weight Poly (ethyleneglycol) Blends in Aqueous Medium

2016 ◽  
Vol 15 (2) ◽  
pp. 45-56
Author(s):  
Sumana V S ◽  
Sudhakar Y N
Keyword(s):  
Molecular Weight ◽  
Refractive Index ◽  
Aqueous Medium ◽  
Low Molecular Weight ◽  
Density Data ◽  
Viscosity Polymer ◽  
Polymer Interaction

The miscibility of starch and poly(ethyleneglycol) (PEG)blends in water were investigated by viscosity, densityand refractive index studies. The physical interactionparameters like poly-solvent and blend-solvent have beencalculated using viscosity and density data. Starch/PEGblends were found to be miscible in all studied ratios. Thestudy also revealed that variation of temperature does notaffect the miscibility of starch and PEG blends in theaqueous solution significantly. The miscibility occurs dueto presence of hydroxyl-hydroxyl interactions in theblends. The result obtained reveals that PEG can beeffectively used as gelating agent in starch solution.Keywords: Miscibility, viscosity, polymer interaction, starch, PEG

Kinetic study of acid depolymerization of chitosan and effects of low molecular weight chitosan on erythrocyte rouleaux formation

2011 ◽  
Vol 346 (1) ◽  
pp. 94-102 ◽  
Author(s):  
Ching Ting Tsao ◽  
Chih Hao Chang ◽  
Yu Yung Lin ◽  
Ming Fung Wu ◽  
Jin Lin Han ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Kinetic Study ◽  
Low Molecular Weight ◽  
Low Molecular Weight Chitosan ◽  
Rouleaux Formation

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
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