scholarly journals Synthesis of cyclic polymers and flaws of the Jacobson–Stockmayer theory

2020 ◽  
Vol 11 (14) ◽  
pp. 2595-2604 ◽  
Author(s):  
Hans R. Kricheldorf ◽  
Steffen M. Weidner ◽  
Felix Scheliga
Keyword(s):  
Monomer Concentration ◽  
Polymer Chains ◽  
Cyclic Polymers ◽  
Initial Monomer Concentration ◽  
Initial Monomer

The results of this study show that even at the highest initial monomer concentration (IMC) complete cyclization of polymer chains can be achieved at 100% conversion.

Microscopic characteristics of Janus nanoparticles prepared via a grafting-from reaction at the immiscible liquid interface

2020 ◽  
Vol 22 (9) ◽  
pp. 5347-5354
Author(s):  
Bing-Yu Li ◽  
Li Zhao ◽  
Zhong-Yuan Lu
Keyword(s):  
Interfacial Tension ◽  
Monomer Concentration ◽  
Immiscible Liquid ◽  
Liquid Interface ◽  
Reaction Probability ◽  
Initial Monomer Concentration ◽  
Janus Nanoparticles ◽  
Initial Monomer ◽  
Grafting From

The interfacial tension, initial monomer concentration, and reaction probability can greatly influence the microscopic characteristics of the Janus nanoparticle (JNP) structure. The asymmetric initial monomer concentration in solution and the reaction probability can be used to control the syntheses of asymmetric JNPs.

scholarly journals Effect of transfer agent, temperature and initial monomer concentration on branching in poly(acrylic acid): A study by 13 C NMR spectroscopy and capillary electrophoresis

Polymer ◽  
2017 ◽  
Vol 114 ◽  
pp. 209-220 ◽  
Author(s):  
Jean-Baptiste Lena ◽  
Alexander K. Goroncy ◽  
Joel J. Thevarajah ◽  
Alison R. Maniego ◽  
Gregory T. Russell ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Nmr Spectroscopy ◽  
Acrylic Acid ◽  
Monomer Concentration ◽  
Initial Monomer Concentration ◽  
Initial Monomer ◽  
C Nmr ◽  
Poly Acrylic Acid

scholarly journals Self-Initiated Butyl Acrylate Polymerizations in Bulk and in Solution Monitored By In-Line Techniques

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2021
Author(s):  
Jonas Mätzig ◽  
Marco Drache ◽  
Sabine Beuermann
Keyword(s):  
High Temperature ◽  
Linear Regression ◽  
Monomer Concentration ◽  
Nir Spectroscopy ◽  
Polymerization Rate ◽  
Additional Parameter ◽  
Initial Monomer Concentration ◽  
Rate Of Polymerization ◽  
Initial Monomer ◽  
Kinetics Of

High-temperature acrylate polymerizations are technically relevant, but yet not fully understood. In particular the mechanism and the kinetics of the thermal self-initiation is a topic of current research. To obtain more detailed information the conversion dependence of the polymerization rate, rbr, is determined via in-line DSC and FT-NIR spectroscopy for reactions in bulk and in solution at temperatures ranging from 80 to 160 °C. Solution polymerizations revealed that dioxane is associated with the highest rbr, while aromatic solvents result in the lowest values of rbr. Interestingly, rbr for polymerizations in solution with dioxane depends on the actual monomer concentration at a given time in the system, but is not depending on the initial monomer concentration. The overall rate of polymerization in bulk and in solution is well represented by an equation with three or four parameters, respectively, being estimated by multiple linear regression and the temperature as additional parameter.

Influence of Reaction Conditions on the Properties of Nano-matrix Structure Formed by Graft-Copolymerization of Acrylonitrile onto Natural Rubber

2013 ◽  
Vol 844 ◽  
pp. 365-368 ◽  
Author(s):  
Kontapond Prukkaewkanjana ◽  
Seiichi Kawahara ◽  
Jitladda Sakdapipanich
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Matrix Structure ◽  
Oil Resistance ◽  
Wide Range ◽  
Initial Monomer

Natural rubber (NR) is one of the most important agriculture products of Thailand, which is an important material with unique and special characteristics used in wide range of applications such as mechanical properties, excellent strength, and elasticity. However, it is inferior in oil resistance due to the presence of hydrogen and carbon in its structure. This inherent drawback of NR has limited its application in industry. In order to expand the use of NR, this research is interested to improve the oil resistance of NR without loss of outstanding properties by grafting NR with acrylonitrile (AN) monomer to form the nano-matrix structure. The influences of the initial monomer concentration and initial initiator concentration were investigated. These effects on structure, mechanical properties and oil resistance properties were studied by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, tensile machine, and swelling in toluene, respectively. It was found that the tensile strength and oil resistance properties of graft copolymerization of AN onto NR increased with increasing the percentage grafting efficiency of acrylonitrile monomer.

Adsorption of linear polymers

1990 ◽  
Vol 68 (9) ◽  
pp. 1089-1093 ◽  
Author(s):  
M. Daoud ◽  
B. Farnoux ◽  
G. Jannink ◽  
A. Johner
Keyword(s):  
Neutron Scattering ◽  
Monomer Concentration ◽  
Polymer Chains ◽  
Linear Polymer ◽  
Linear Polymers ◽  
Fixed End ◽  
Scaling Arguments

Linear polymer chains usually interact strongly with surfaces. Various regimes are obtained when one varies the bulk monomer concentration C or the interaction δ of a monomer with the surface. We discuss the recent results that were obtained theoretically by scaling arguments and compare them with hydrodynamic, neutron-scattering, and reflectivity measurements. Although the agreement is satisfactory in some cases, no general agreement has been reached so far. We also discuss the relaxation of the streched chain when the fixed end constraint is released. Possible experimental realizations are given.

scholarly journals Rheological Properties in Aqueous Solution for Hydrophobically Modified Polyacrylamides Prepared in Inverse Emulsion Polymerization

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Shirley Carro ◽  
Valeria J. Gonzalez-Coronel ◽  
Jorge Castillo-Tejas ◽  
Hortensia Maldonado-Textle ◽  
Nancy Tepale
Keyword(s):  
Emulsion Polymerization ◽  
Shear Viscosity ◽  
Hydrophobic Interactions ◽  
Monomer Concentration ◽  
Feed Composition ◽  
Inverse Emulsion Polymerization ◽  
Inverse Emulsion ◽  
Hydrophobically Modified ◽  
Initial Monomer ◽  
Modified Polyacrylamide

Inverse emulsion polymerization technique was employed to synthesize hydrophobically modified polyacrylamide polymers with hydrophobe contents near to feed composition. Three different structures were obtained: multisticker, telechelic, and combined. N-Dimethyl-acrylamide (DMAM), n-dodecylacrylamide (DAM), and n-hexadecylacrylamide (HDAM) were used as hydrophobic comonomers. The effect of the hydrophobe length of comonomer, the initial monomer, and surfactant concentrations on shear viscosity was studied. Results show that the molecular weight of copolymer increases with initial monomer concentration and by increasing emulsifier concentration it remained almost constant. Shear viscosity measurements results show that the length of the hydrophobic comonomer augments the hydrophobic interactions causing an increase in viscosity and that the polymer thickening ability is higher for combined polymers.

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