Polymerization effect

In vitro culture isolated brain cells exposed for 20 h to graded concentrations of nickel chloride up to 116 mg Ni/L DOMESTIC DOG, Canis familiaris Diet Time- and dose-dependent effects on kinetics of brain microtubule polymerization effects reversed on removal of Ni2+ from culture media 4... 

Turgman-Cohen, S. and J. Genzer, Computer simulation of controlled radical polymerization Effect of chain confinement due to initiator grafting density and solvent quality in "grafting from Method. Macromolecules, 2010. 43(22) p. 9567-9577. 

Tang W, Kwak Y, Braunecker W et al. (2008) Understanding atom transfer radical polymerization effect of ligand and initiator structures on the equilibrium constants. J Am Chem Soc 130 10702-10713... 

Frequently, even if as little as 20% of the monomer has polymerized, an autoaccelerating polymerization effect will take place. This may manifest itself in an increase in the heat evolved as the process nears completion. Particularly in large-scale, industrial polymerizations, this effect, known as the Trommsdorff effect or gel effect, may be quite dangerous. In fact, serious explosions have... 

The temperature of treatment with sulfuric acid has an important effect on the quality and yield of the product. By the use of low temperature and proper conditions of contact, it is possible to cut down the polymerizing effect of acid on olefins, thus reducing losses without impairing its solvent power for sulfur compounds. 

The bulk polymerization effects the special needs to remove the heat of reactions, and moreover, high conversions cannot be reached because the viscosity of the polymer increases drastically with conversion. In order to avoid a high viscosity of the end product before discharging, the mass polymerization is carried out in solution. Ethylbenzene is a common solvent. 

Catalytic activities of these complexes for the polymerization of propylene oxide were tested. The pyridine complex had no catalytic activity, whereas the diethyl ether or dioxane complex had activity comparable to that of the mother organozinc compound. This fact indicates that a strong electron donor which cannot be replaced by propylene oxide inhibits the polymerization effectively. Thus, the co-... 

Diffusion-Controlled Free Radical Polymerization - Effect on Polymerization Rate and Molecular Properties of PVC , Abstracts - Third International Symposium on PVC, Case Western Reserve University, Cleveland, August 10-15 (1980). 

Paushkin and Lipatov (286) added 10% boron fluoride to silica-alumina and to activated charcoal for use in cracking a crude oil fraction at 310-510°. Over silica-alumina at 400° or higher the amount of olefins was about half that obtained with silica-alumina alone. The amount of gasoline obtained was increased 15 % or more. In the case of charcoal, the polymerizing effect of boron fluoride reduced the yield and increased the specific gravity. 

Tt is well known that the presence of precipitated polymer can influence the course of polymerization. In bulk acrylonitrile polymerization the effects are most dramatic and have been the subject of many studies. The literature on this subject has been reviewed by Bamford et al. (4) by Thomas (29), and by Peebles (23). Under conditions where the system becomes heterogeneous owing to precipitation of small particles of polymer, a protracted acceleration period is observed at the start of polymerization, and the final rate is found to depend on the 0.8 power of the concentration of free radical initiator. Unusual post-polymerization effects are observed in photoinitiated polymerization of acrylonitrile, owing to the presence of trapped radicals which can be detected by electron spin resonance. None of the detailed mechanisms proposed to... 

The color change and the sensitivity of conversion to order of addition of monomers and peroxide indicate that in order to obtain an AFR polymer the polar monomers must first be complexed or allowed to react with the active or living end of the anionic polymer chain, or otherwise solvate it before the polymer chain is attacked by the peroxide. Success or failure of the subsequent free radical block polymerization depends on the nature of the complex or reaction product formed. The resultant species are no longer active for propylene polymerization. The necessity of complex formation has also been observed by Milovskaya and coworkers (4). They have shown that vinyl chloride, a weak complexing agent, can be polymerized effectively with triethylaluminum peroxide only when it is present with a more active complexing compound such as an ester or an ether. 

CO Polymerization Effect of Conversion on Low Molecular Weight Macrocyclics. A series of polymerizations of cyclooctene was carried out in a manner similar to that described above, using a constant monomer concentration of 1.57M. The polymerizations were terminated at various reaction times, thus obtaining different conversions. The products were isolated, processed, and analyzed for percent extractable macrocyclics as described previously. 

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