Change in molecular weight characteristics of an aromatic copolyamide during the polycondensation process

1989 ◽  
Vol 21 (2) ◽  
pp. 133-135
Author(s):  
O. I. Manina ◽  
L. M. Braginskaya ◽  
V. I. Komissarov ◽  
S. V. Shorin ◽  
I. F. Kuyantseva ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Characteristics ◽  
Polycondensation Process

scholarly journals A Versatile Equilibrium Method for the Synthesis of High-Strength, Ladder-like Polyphenylsilsesquioxanes with Finely Tunable Molecular Parameters

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4452
Author(s):  
Tatyana O. Ershova ◽  
Anton A. Anisimov ◽  
Maxim N. Temnikov ◽  
Maxim A. Novikov ◽  
Mikhail I. Buzin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liquid Ammonia ◽  
Reaction Medium ◽  
Monomer Concentration ◽  
High Strength ◽  
29Si Nmr ◽  
Molecular Weights ◽  
Equilibrium Method ◽  
Molecular Weight Characteristics ◽  
Polycondensation Process

A versatile equilibrium method for synthesizing ladder-like polyphenylsilsesquioxanes (L-PPSQs) with various molecular weights (from 4 to 500 kDa) in liquid ammonia was developed. The effect of diverse parameters, such as temperature, monomer concentration, reaction time, addition or removal of water from the reaction medium, on the polycondensation process was determined. The molecular weight characteristics and structure of the L-PPSQ elements obtained were determined by GPC, 1H, 29Si NMR, IR spectroscopy, viscometry, and PXRD methods. The physicochemical properties of L-PPSQs were determined by TGA and mechanical analyses.

Synthesis and molecular-weight characteristics of n-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers

2012 ◽  
Vol 46 (8) ◽  
pp. 478-481 ◽  
Author(s):  
S. A. Kedik ◽  
A. V. Panov ◽  
I. V. Sakaeva ◽  
Yu. V. Kochkina(Cherta) ◽  
D. V. Eremin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Characteristics

CATIONIC COPOLYMERIZATION OF ISOBUTYLENE WITH ISOPRENE: KINETICS OF THE PROCESS AND DETERMINATION OF KINETIC CONSTANTS

2015 ◽  
Vol 88 (4) ◽  
pp. 574-583 ◽  
Author(s):  
N. V. Ulitin ◽  
K. A. Tereshchenco ◽  
D. A. Shiyan ◽  
G. E. Zaikov
Keyword(s):  
Experimental Data ◽  
Molecular Weight ◽  
Cationic Polymerization ◽  
Methyl Chloride ◽  
Theoretical Description ◽  
Kinetic Constants ◽  
Molecular Weight Characteristics ◽  
Cationic Copolymerization ◽  
Kinetics Of

ABSTRACT A theoretical description has been developed of the kinetics of isobutylene with isoprene (IIR) cationic polymerization in the environment of methyl chloride on aluminum trichloride as the catalyst. Based on experimental data on the kinetics of copolymerization (isobutylene conversion curve) and the molecular weight characteristics of the copolymer of IIR, kinetic constants for the process were found. Adequacy of the developed theoretical description of the kinetics of the IIR copolymerization process was confirmed by comparing the experimental molecular-weight characteristics calculated by this description, independent characteristics, and IIR unsaturation.

Melt fracture of linear low-density polyethylenes: Die geometry and molecular weight characteristics

2018 ◽  
Vol 30 (5) ◽  
pp. 053103 ◽  
Author(s):  
Marzieh Ebrahimi ◽  
Tanja Tomkovic ◽  
Guochang Liu ◽  
Antonios A. Doufas ◽  
Savvas G. Hatzikiriakos
Keyword(s):  
Molecular Weight ◽  
Low Density ◽  
Melt Fracture ◽  
Die Geometry ◽  
Molecular Weight Characteristics
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