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Reversible gelation of acrylonitrile–vinyl acetate copolymer solutions. II. Mechanical properties
Author(s) -
Paul D. R.
Publication year - 1967
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.1967.070110911
Subject(s) - acrylonitrile , copolymer , vinyl acetate , materials science , polymer chemistry , solvent , dimethylacetamide , chemical engineering , polymer , dynamic mechanical analysis , composite material , chemistry , organic chemistry , engineering
Concentrated solutions of acrylonitrile polymers exhibit reversible gelation. The rate of gelation at 25°C. was determined for various solutions of an acrylonitrile copolymer containing 7.7% vinyl acetate in mixtures of dimethylacetamide (solvent) and water (nonsolvent) by measuring the shear modulus of the forming gel as a function of time. The mechanical properties were also measured on a series of gels formed by cooling solutions to −78°C. It was found that both the rate of gelation at 25°C. and the modulus of gels formed at −78°C. increase very rapidly as either the solids level of the solution of the water content of the solvent is increased. The gelation rate data wree correlated with the gel melting points of the gels. The results are discussed and compared with the analogous but limited data available for other systems.