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Physical and surface properties of aqueous solutions of polyvinyl alcohols having an n ‐alkylthio end group
Author(s) -
Sato Toshiaki,
Okaya Takuji
Publication year - 1992
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.1992.070460411
Subject(s) - aqueous solution , polyvinyl alcohol , chemistry , polymer chemistry , emulsion polymerization , polymerization , osmometer , emulsion , carbon fibers , molecule , organic chemistry , materials science , polymer , composite number , composite material
The polyvinyl alcohols (PVAs) having a n ‐alkylthio end group of 10 through 16 carbon atoms were found to associate in the dilute aqueous solutions through hydrophobic interaction. From the apparent number‐average molecular weight with vapor pressure osmometer, the PVAs having an n ‐dodecylthio and an n ‐hexadecylthio group at one end were calculated to associate by about five and three molecules, respectively. The aqueous solutions of the PVA having an n ‐dodecylthio group at one end showed much higher viscosity compared with the PVA having a hydroxyethylthio group at one end (HOCH 2 CH 2 S—PVA) in low concentration regions of below 10 wt % due to the association of the n ‐dodecyl end group. Surface tensions of the aqueous solutions of the PVAs having an n ‐alkylthio group at one end ( n ‐C n H 2 n +1 S—PVA) showed almost the same value, which was slightly smaller than that of HOCH 2 CH 2 S—PVA, at 4 and 6 of carbon atoms, lowered with an increase in the number of carbon atoms above 8, showed minimum at 12 and then increased at 16 and 18. In the emulsion polymerization of vinyl acetate, n ‐C n H 2 n +1 S—PVAs of 10 through 18 carbon atoms acted effectively as a protective colloid.