Premium
Alkaline hydrolysis of polyacrylonitrile, 2. On the product swelling
Author(s) -
Kudryavtsev Yaroslav V.,
Krentsel Liya B.,
Bondarenko Gali.,
Litmanovich Arkady D.,
Platé Nicolai A.,
Schapowalow Sergei,
Sackmann Guenter
Publication year - 2000
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20000801)201:13<1419::aid-macp1419>3.0.co;2-3
Subject(s) - polyacrylonitrile , swelling , hydrolysis , polymer chemistry , chemistry , acrylonitrile , polyacrylamide , counterion , aqueous solution , alkali metal , alkaline hydrolysis , polymer , polyelectrolyte , reaction rate constant , kinetics , organic chemistry , materials science , composite material , ion , copolymer , physics , quantum mechanics
The swelling capacities of alkali hydrolyzed polyacrylonitrile in water Q w and in 0.9 wt.‐% NaCl aqueous solution Q s were measured. Using these data the fraction of crosslinked units is estimated to vary from 0.8 to 1.6% for different samples. The analysis of Q s dependence on Q w is proposed as a method to estimate the degree of polymer network ionization α . The α value is found to be approximately 0.36 for all samples at the degree of neutralization 0.49–0.70. This indicates that a significant part of counterions does not affect the swelling, being bound by polyions. The influence of the conditions of hydrolysis (polymer/alkali and water/ethanol ratios) on the swelling properties of the product and the nature of crosslinks are discussed. Interchain interaction of an amidine group and an acrylonitrile unit resulting in a formation of β ‐diketone‐like structure is proposed to explain the crosslinking. Kinetic measurements were carried out to estimate the ratio of the initial rate constants for the polyacrylonitrile and polyacrylamide alkaline hydrolysis which was found to be of order 10 –1 .