Analysis of dissolution kinetics of poly(4-hydroxystyrene) with different molecular weight distributions in alkaline aqueous solution using machine learning

2021 ◽  
Author(s):  
Naoki Tanaka ◽  
Kyoko Watanabe ◽  
Kyoko Matsuoka ◽  
Kazuki Azumagawa ◽  
Takahiro Kozawa ◽  
...  
Keyword(s):  
Machine Learning ◽  
Aqueous Solution ◽  
Molecular Weight ◽  
Dissolution Kinetics ◽  
Molecular Weight Distributions ◽  
Alkaline Aqueous Solution ◽  
Weight Distributions ◽  
Kinetics Of ◽  
Different Molecular Weight

scholarly journals Oligomeric alkylpyridinium surfactants prepared via ATRP

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Su ◽  
Zonglin Chu ◽  
Ya Shuai ◽  
Zanru Guo ◽  
Yujun Feng
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Aqueous Media ◽  
Degree Of Polymerization ◽  
Surface Activities ◽  
H Nmr ◽  
Molecular Weight Distributions ◽  
Weight Distributions

AbstractA series of oligomeric alkylpyridinium surfactants were prepared directly in aqueous media by atom transfer radical polymerization (ATRP) of a surfmer, 4- vinyl-N-dodecylpyridinium bromide, and their surface activities were examined in comparison with the surfmer. The resulting oligomers have narrow molecular weight distributions, with polydispersity indices in the range of 1.17-1.23. By using 2-morpholinoethyl 2-bromo-2-methylpropanoate as ATRP initiator, the molecular weight of oligomeric surfactants was characterized by 1H NMR and the results were close to those obtained from GPC analysis. It was found that critical micelle concentration (CMC) of the oligomeric alkylpyridinium surfactants shifted to lower concentrations with increasing degree of polymerization (DPn), and their γ-cmc values were smaller by about 4 to 8 mN/m than that of the corresponding surfmer. Among the series of surfactants, the oligomer with highest DPn showed the greatest efficiency in lowering the surface tension in aqueous solution.

The Mechanism Which Restricts Chain Growth in Polymerization with Alkylaluminum-Titanium Tetrachloride Complex Catalysts

1961 ◽  
Vol 34 (3) ◽  
pp. 986-990
Author(s):  
S. E. Bresler ◽  
M. I. Mosevitskiĭ ◽  
I. Ya Poddubnyĭ ◽  
Shi Guan-I
Keyword(s):  
Molecular Weight ◽  
Regular Structure ◽  
Chain Growth ◽  
Time Interval ◽  
Stationary Condition ◽  
Kinetics Of Polymerization ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
Kinetics Of ◽  
Isoprene Polymerization

Abstract In the production of polymers having a highly regular structure of the molecular chains, catalyst complexes of the Ziegler type are currently in wide use. The development of mechanisms for the separate steps in the catalytic process is of primary significance. This report outlines some results on a study of the mechanisms involved in isoprene polymerization with complexes formed through the interaction of Al (iso-C4H9)3 and TiCl4; the data were obtained from the sedimentation of the polymers in the ultracentrifuge, in combination with data on the kinetics of polymerization. We have indicated previously1 that in isoprene polymerization using the specified catalysts, the growth of the macromolecules proceeds quite rapidly, the time interval between the first appearance of active chains and the termination of reaction being only a few minutes; subsequently there follows an immediate stationary condition. However, with use of the ultracentrifuge we have obtained molecular weight distributions of polymers which are substantially different from the equilibrium distribution expected from present-day kinetic theories of polymerization. They were characterized by relatively low dispersion and, in the main, strongly distorted by high-molecular bands; in most cases, there was practically a complete absence of molecules with a molecular weight less than 200–300 thousand.

Sign in / Sign up

Export Citation Format

Share Document