Download or read book A Study of the Kinetics of Polymerization of Styrene Initiated with Ethyllithium written by Wing Y. Fung and published by . This book was released on 1959 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Kinetics of Nitroxide Mediated Radical Polymerization of Styrene with a Unimolecular Initiator written by Mingxiao Zhou and published by . This book was released on 2009 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the results of a study on the kinetics of nitroxide-mediated radical polymerization of styrene with a unimolecular initiator. The primary objective was to obtain a more comprehensive understanding of how a unimolecular-initiating system controls the polymerization process and to clarify the effects of various reaction parameters. Previous work in this field has met with some difficulties in the initiator synthesis, such as low yield and inconsistency of molecular weight. These problems were overcome by adjusting reaction conditions and procedures. Better yields of initiator with consistent molecular weight were produced by the improved methods. Control of polymerization rate and polymer molecular weight in unimolecular nitroxide-mediated radical polymerization was studied by looking at the effects of the three main factors: initiator concentration, temperature, and the initiator molecular weight on polymerization rate, molecular weight and polydispersity. Results indicated that increasing the initiator concentration had no effect on polymerization rate at low conversion, but led to lower polymerization rate at high conversion; higher initiator concentration led to lower molecular weight of the resulting polymer. It was also found that temperature significantly increased the polymerization rate, yet had no effect on number-average molecular weight, Mn, at low conversion, while it caused a plateau at high conversion levels; there was no effect on weight-average molecular weight, Mw, through the whole conversion range. In addition, increasing initiator molecular weight was found to have no effect on either polymerization rate or molecular weight. The experimental molecular weights of the unimolecular system were compared to theoretical molecular weights based on ideal controlled radical polymerization (CRP). The results were found to be close to the theoretical values. This confirmed the advantages of the unimolecular system, namely, the degree of control over molecular weight was nearly ideal (for certain conditions); and molecular weights could thus be predicted by simply following general rules relating to CRP mechanisms.

Download or read book Kinetics of Polymerization of Styrene Initiated by the System Benzoyl Peroxide Dimethyl Aniline written by T. H. Meltzer and published by . This book was released on 1954 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Masters Theses and Doctoral Dissertations in the Pure and Applied Sciences Accepted by Colleges and Universities of the United States written by and published by . This book was released on 1959 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymerization of Styrene by Ethyllithium written by Shiao-ping Siao and published by . This book was released on 1959 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanism of Initiation in the Thermal Polymerization of Styrene Kinetic Deuterium Isotope Effects in the Initiation Step of the Thermal Polymerization of Some Deuterated Styrenes written by Karl R. Kopecky and published by . This book was released on 1969 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A convenient synthesis of 2,6-dideuteriostyrene starts with N, N-dimethyl-(1-phenylethyl)-amine which is deuterated in the 2 and 6 positions by a series of exchanges using n-butyllithium followed by deuterium oxide. The deuterium isotope effects at 70C on the rates of the thermal polymerization, of 2,6-dideuterio-, alpha-deuterio-, and beta, beta-dideuteriostyrene are 1.29, 1.00, and 0.78, respectively. The deuterium isotope effects at 70C on the 2,2'-azobis(2-methylpropionitrile) initiated rates of polymerization, are 0.96, 0.86, and 0.81, respectively. From these values the deuterium isotope effects on the rates of initiation of the thermal polymerization, k(iH)/k(iD), are calculated to be 1.80, 1.31, and 0.92, respectively. At 147C the presence of 1.5% potassium t-butoxide decreases the rate of the thermal polymerization of neat styrene by a factor of 17, and results in the formation of 1-phenyltetralin as the greatly predominant dimer. The results support the suggestion that the thermal polymerization of styrene is initiated by hydrogen transfer from 1-phenyl-1,2,3,9-tetrahydronaphthalene, formed by a concerted dimerization of two molecules of styrene, to a third molecule of styrene. (Author).

Download or read book Synthesis and Kinetics of Decomposition of Bridged Bicyclic Azo Compounds and Kinetics of Polymerization of Styrene Initiated by Diphenylmethyl Radicals written by Robert Zand and published by . This book was released on 1961 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Living Anionic Polymerization of Styrene and 1 3 butadiene in Ethylbenzene written by Stephane Auguste and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The kinetics of the n-butyllithium initiated polymerization of styrene and 1,3-butadiene in ethylbenzene has been studied for the first time under industrially relevant conditions of concentration and temperature. Raman spectroscopy has been used to follow the monomer concentration over a wide range of conversions, and UV spectroscopy to follow the appearance of the propagating live-ends with time. The apparent rate constants for the initiation and propagation reactions in the polymerization of styrene in ethylbenzene have been determined and their activation energies evaluated. The propagation rate constant in the polymerization of I,3-butadiene in ethylbenzene has also been determined. A quantitative study of the livingness of polystyryllithium and polybutadienyllithium live-ends in ethylbenzene at temperatures above 50 has been carried out for the first time, using both UV spectroscopy and viscometry to measure the rate of change of polyanion concentration. It has been shown that polystyryllithium live-ends are more stable than polybutadienyllithium live-ends. A mechanism of chain-transfer to the solvent has been proposed and a comparison with the stability of the live-ends in cyclohexane has been done. Linear homopolymers, linear and star-shaped block copolymers of styrene and 1,3-butadiene are of particular industrial interest and have been synthesized in the present work, and characterized using conventional gel permeation chromatography and differential viscometry. Finally, a modelling package has been used to simulate the effect of feed perturbations on the molecular weight and molecular weight distribution of living polymers synthesized in a continuous stirred tank reactor undergoing periodic feed oscillations. The effect on the dispersity index of the polymer produced of the pulse(s) parameters have been studied and some predictions confirmed experimentally using the alkyllithium initiated polymerization of styrene, that was carried out in a computer controlled continuous flow stirred tank reactor (CSTR).

Download or read book Proceedings of the Academy of Sciences of the USSR written by Академия наук СССР and published by . This book was released on 1962 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Master s Theses and Doctoral Dissertations in the Pure and Applied Sciences written by and published by . This book was released on 1959 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinetics and Mechanism of Triethylamine Initiated Polymerization of Ethyl 2 cyanoacrylate in Dioxane written by Kerming Tsaur and published by . This book was released on 1975 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinetics of the Anionic Polymerization of Styrene written by Ronald Turner Laflair and published by . This book was released on 1965 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Masters Theses in the Pure and Applied Sciences Accepted by Colleges and Universities of the United States written by and published by . This book was released on 1960 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinetics Study written by James D. Joyce and published by . This book was released on 1968 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling and Control of the Polymerisation of Styrene written by T. M. Raja and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book English Abstracts of Selected Articles from Soviet Bloc and Mainland China Technical Journals written by and published by . This book was released on 1962 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinetics of the Benzoin Isobutyl Ether Photoinitiated Polymerization of Styrene written by Yassin Yusef Tarshiani and published by . This book was released on 1984 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: