Premium
Crosslinking aqueous poly(vinyl pyrrolidone) solutions by persulfate
Author(s) -
Anderson C. C.,
Rodriguez F.,
Thurston D. A.
Publication year - 1979
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1979.070230823
Subject(s) - potassium persulfate , aqueous solution , persulfate , materials science , polymer , modulus , polymer chemistry , shear modulus , chemical engineering , chemistry , composite material , organic chemistry , polymerization , catalysis , engineering
Aqueous solutions with 1.5 to 6.5 wt‐% poly(vinyl pyrrolidone), PVP, are converted to stable gels by reaction with potassium persulfate. Large quantities of persulfate are needed for high‐modulus gels, 50% to 150% of the weight of PVP being required typically. The shear modulus G ′ can be measured during reaction by making the gel the restoring element in a simple torsion pendulum. The increase in modulus to a maximum plateau value of G ′ max can be expressed as a first‐order process:\documentclass{article}\pagestyle{empty}\begin{document}$$ - \ln [1 - (G'/G'_{\max } )] = Kt $$\end{document} Where t is elapsed time of reaction and K increases with the square root of polymer concentration. G ′ max varies with the second power of the polymer concentration. It also increases rapidly with increasing temperature of reaction and with persulfate/PVP ratio.