Premium
Batch emulsion copolymerization of 50/50 vinyl acetate/ n‐butyl acrylate using poly(vinyl alcohol) emulsifier
Author(s) -
Vanderhoff J. W.,
Earhart N. J.,
Dimonie V. L.,
ElAasser M. S.
Publication year - 1990
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19900350129
Subject(s) - vinyl acetate , copolymer , vinyl alcohol , polymer chemistry , acrylate , butyl acrylate , reactivity (psychology) , emulsion polymerization , hydrolysis , vinyl polymer , chemistry , emulsion , materials science , organic chemistry , polymer , medicine , alternative medicine , pathology
In the batch emulsion copolymerization of 50/50 vinyl acetate/n‐butyl acrylate mixture, no emulsifier or sodium lauryl sulfate emulsifier gave a n‐butyl acrylate‐rich copolymer until the n‐butyl acrylate became depleted, and a vinyl acetate‐rich copolymer and poly(vinyl acetate) thereafter, as expected from the disparate copolymerization reactivity ratios (r 1 0.05; r 2 5). In contrast, poly(vinyl alcohol) emulsifier gave an initial polymerization of vinyl acetate at a rate equal to or greater than that of the n‐butyl acrylate up to 7–37% conversion; then, the n‐butyl acrylate polymerized preferentially until it became depleted, followed by the remaining vinyl acetate, to give a vinyl acetate‐rich copolymer and poly(vinyl acetate), as expected from the copolymerization reactivity ratios. The mechanism proposed for this process comprised the grafting of vinyl acetate on the poly(vinyl alcohol) in solution to give a water‐insoluble graft copolymer, which precipitated and served as the locus for nucleation of poly(n‐butyl acrylate)‐rich particles. Fully hydrolyzed poly(vinyl alcohol) required a higher degree of grafting to give a water‐insoluble graft copolymer than partially hydrolyzed poly(vinyl alcohol).