Kinetics of the anionic polymerization of 2-(tertbutyldimethylsilyloxy) ethyl methacrylate

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Thomas Breiner ◽  
Hans-Werner Schmidt ◽  
Axel H. E. Müller
Keyword(s):  
Anionic Polymerization ◽  
Gel Permeation Chromatography ◽  
Butyl Methacrylate ◽  
Side Reactions ◽  
Polymerization Temperature ◽  
Hydroxyethyl Methacrylate ◽  
Controlled Polymerization ◽  
Ethyl Methacrylate ◽  
Reported Data ◽  
Kinetics Of

AbstractThe kinetics and the extent of side reactions of the anionic polymerization of silyl-protected 2-hydroxyethyl methacrylate, 2-(tert-butyldimethylsilyloxy)ethyl methacrylate (TBDMS-HEMA), in tetrahydrofuran (THF) were studied as a function of polymerization temperature. Lithium chloride was added in order to achieve a controlled polymerization. The results of polymerizations at various temperatures are compared with reported data for methyl methacrylate and tert-butyl methacrylate in THF. The activation energy for the studied monomer is lower compared to the other methacrylates. Gel permeation chromatography-viscosity studies show that poly(TBDMS-HEMA) exhibits a more wormlike structure in THF than other polymethacrylates, as indicated by a higher Mark-Houwink exponent, α = 1.025.

scholarly journals Polystyrene-b-Poly(2-(Methoxyethoxy)ethyl Methacrylate) Polymerization by Different Controlled Polymerization Mechanisms

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3505
Author(s):  
Dragutin Nedeljkovic
Keyword(s):  
Block Copolymers ◽  
Radical Polymerization ◽  
Anionic Polymerization ◽  
Average Molecular Weight ◽  
Side Reactions ◽  
Controlled Polymerization ◽  
Ethyl Methacrylate ◽  
Structures And Properties ◽  
Important Field ◽  
Atomic Transfer Radical Polymerization

Functional polymers have been an important field of research in recent years. With the development of the controlled polymerization methods, block-copolymers of defined structures and properties could be obtained. In this paper, the possibility of the synthesis of the functional block-copolymer polystyrene-b-poly(2-(methoxyethoxy)ethyl methacrylate) was tested. The target was to prepare the polymer of the number average molecular weight (Mn) of approximately 120 that would contain 20–40% of poly(2-(methoxyethoxy)ethyl methacrylate) by mass and in which the polymer phases would be separated. The polymerization reactions were performed by three different mechanisms for the controlled polymerization—sequential anionic polymerization, atomic transfer radical polymerization and the combination of those two methods. In sequential anionic polymerization and in atomic transfer radical polymerization block-copolymers of the desired composition were obtained but with the Mn significantly lower than desired (up to 30). The polymerization of the block-copolymers of the higher Mn was unsuccessful, and the possible mechanisms for the unwanted side reactions are discussed. It is also concluded that combination of sequential anionic polymerization and atomic transfer radical polymerization is not suitable for this system as polystyrene macroinitiator cannot initiate the polymerization of poly(2-(methoxyethoxy)ethyl methacrylate).

Kinetics of quaternization reactions of polymeric amines

1989 ◽  
Vol 54 (3) ◽  
pp. 663-672
Author(s):  
Martin Přádný ◽  
Stanislav Ševčík ◽  
Stela Dragan
Keyword(s):  
Alkylating Agent ◽  
Alkyl Halides ◽  
Differential Rate ◽  
Hydroxyethyl Methacrylate ◽  
Ethyl Methacrylate ◽  
Slowing Down ◽  
Conformational Effects ◽  
Alkylation Reactions ◽  
Kinetics Of ◽  
Steric Hindrances

The paper deals with kinetics phenomena occurring in the quaternization of some polymeric amines, such as poly[2-(dimethylamino)ethyl methacrylate], poly{N-[3-(dimethylamino)propyl]-acrylamide}, and poly[2-(dimethylamino)ethyl methacrylate-co-2-hydroxyethyl methacrylate], with alkyl halides. The accelerating and slowing-down effects which take place in the alkylation reactions are discussed on the basis of the reaction course, i.e. of the dependence of differential rate constants on the conversion fraction of the reaction. Accelaration of the reaction is affected by the increasing polarity of microsurroundings of the reacting groups, while electrostatic and steric hindrances of the reacted groups slow down the reaction. Conformational effects, chemical and solvation interactions in the polymer-solvent-alkylating agent system and tacticity of the polymer are also operative.

Controlled grafting of poly(styrene-ran-n-butyl methacrylate) to isotactic polypropylene with nitroxidemediated polymerization

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Yusuke Sugino ◽  
Katsuhiro Yamamoto ◽  
Youhei Miwa ◽  
Masato Sakaguchi ◽  
Shigetaka Shimada
Keyword(s):  
Isotactic Polypropylene ◽  
Graft Polymerization ◽  
Reaction System ◽  
Gel Permeation Chromatography ◽  
Butyl Methacrylate ◽  
Molecular Characteristics ◽  
Polymerization Temperature ◽  
Local Concentration ◽  
Γ Irradiation ◽  
Polymerization Method

Abstract A nitroxide (2,2,6,6-tetramethylpiperidin-1-oxyl, TEMPO) mediated polymerization method was applied to the graft polymerization of styrene (ST)/ n-butyl methacrylate (BMA) to isotactic polypropylene (PP). PP peroxides produced by γ-irradiation in air were used as macroinitiator for grafting. The molecular characteristics of grafted and free poly(ST-r-BMA) chains were analysed by gel permeation chromatography, NMR and IR measurements. The molecular weight of grafted poly(ST-r-BMA) cleaved from PP was slightly higher than that of free poly(ST-r-BMA) generated simultaneously in the reaction system. Polydispersities of these polymers were narrow, indicating that grafting proceeded in a living fashion. The incorporated amount of BMA into grafted poly(ST-r-BMA) was smaller than that of free poly(ST-r-BMA). It is considered that the local concentration of BMA around propagating ends of graft poly(ST-r-BMA) was lower than that around free poly(ST-r-BMA) because PP cannot be dissolved in BMA monomer but in ST monomer at the polymerization temperature.

scholarly journals Kinetics of Non-Enzymatic Synthesis of Dipeptide Cbz-Phe-Leu with AOT Reversed Micelles

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1003
Author(s):  
Michiaki Matsumoto ◽  
Tadashi Hano
Keyword(s):  
Enzymatic Synthesis ◽  
Maximum Yield ◽  
Side Reactions ◽  
Experimental Conditions ◽  
Operational Conditions ◽  
Ph Dependency ◽  
Optimum Water Content ◽  
Short Time ◽  
Kinetics Of ◽  
Aot Reversed Micelles

The non-enzymatic synthesis of N-benzyloxycarbonyl-L-phenylalanyl-L-leucine (Cbz-Phe-Leu) from lipophilic N-benzyloxycarbonyl-L-phenylalanine (Cbz-Phe) and hydrophilic L-leucine (Leu), by N, N’-dicyclohexylcarbodiimide (DCC) as a condensing agent, was carried out using a reversed micellar system composed of bis(2-ethylhexyl) sodium sulfosuccinate (AOT) as a surfactant and isooctane. We successfully synthesized Cbz-Phe-Leu in a short time and investigated the effects of its operational conditions, the DCC concentration, w0, and the pH on the kinetic parameters and the maximum yields. For dipeptide synthesis, we had to add an excess of DCC with the substrates because of the side reactions of Cbz-Phe. From the pH dependency of the reactivity, a partially cationic form of Leu was better for a synthesis reaction because of the enrichment of Leu at the interface by anionic AOT. The optimum water content on the dipeptide synthesis was w0 = 28 due to the competition of the peptide synthesis and the side reactions. The maximum yield of Cbz-Phe-Leu was 0.565 at 80 h under optimum experimental conditions.

Kinetics of the Anionic Polymerization of Buta-1,3-diene Considering Different Reactivities of the cis, trans and vinyl Structural Units

2008 ◽  
Vol 2 (5) ◽  
pp. 436-451 ◽  
Author(s):  
José A. Tenorio López ◽  
Juan J. Benvenuta Tapia ◽  
Celestino Montiel Maldonado ◽  
Leonardo Ríos Guerrero
Keyword(s):  
Anionic Polymerization ◽  
Structural Units ◽  
Kinetics Of

Kinetics of the temperature-induced volume phase transition in poly(2-(2-methoxyethoxy)ethyl methacrylate) hydrogels of various topologies

Polymer ◽  
2017 ◽  
Vol 110 ◽  
pp. 25-35 ◽  
Author(s):  
Marcin Pastorczak ◽  
Lidia Okrasa ◽  
Jeong Ae Yoon ◽  
Tomasz Kowalewski ◽  
Krzysztof Matyjaszewski
Keyword(s):  
Phase Transition ◽  
Volume Phase Transition ◽  
Volume Phase ◽  
Ethyl Methacrylate ◽  
Kinetics Of

Probing the molecular weights of sweetgum and pine kraft lignin fractions

TAPPI Journal ◽  
2021 ◽  
Vol 20 (6) ◽  
pp. 381-391
Author(s):  
JULIANA M. JARDIM ◽  
PETER W. HART ◽  
LUCIAN LUCIA ◽  
HASAN JAMEEL
Keyword(s):  
Molecular Weight ◽  
Black Liquor ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Systematic Investigation ◽  
Kraft Pulping ◽  
Molecular Weights ◽  
Lignin Recovery ◽  
Lignin Reactivity ◽  
Kinetics Of

The present investigation undertook a systematic investigation of the molecular weight (MW) of kraft lignins throughout the pulping process to establish a correlation between MW and lignin recovery at different extents of the kraft pulping process. The evaluation of MW is crucial for lignin characterization and utilization, since it is known to influence the kinetics of lignin reactivity and its resultant physicochemical properties. Sweetgum and pine lignins precipitated from black liquor at different pHs (9.5 and 2.5) and different extents of kraft pulping (30–150 min) were the subject of this effort. Gel permeation chromatography (GPC) was used to deter- mine the number average molecular weight (Mn), mass average molecular weight (Mw), and polydispersity of the lignin samples. It was shown that the MW of lignins from both feedstocks follow gel degradation theory; that is, at the onset of the kraft pulping process low molecular weightlignins were obtained, and as pulping progressed, the molecular weight peaked and subsequently decreased. An important finding was that acetobromination was shown to be a more effective derivatization technique for carbohydrates containing lignins than acetylation, the technique typically used for derivatization of lignin.

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