E. Mendizabal et al., Effect of pH on the mechanical properties of functionalized polymers prepared by emulsion polymerization, J APPL POLY, 74(14), 1999, pp. 3299-3304
The influence of pH on the incorporation of a functional monomer (itaconic
acid or methacrylic acid) on core-shell polymers of styrene-butyl acrylate
and on their mechanical properties is investigated. The structured polymers
were prepared by a two-stage emulsion polymerization process. It was found
that the composition of the shell is strongly affected by the pH of the re
acting medium. The amount of functional monomer that is incorporated in the
shell increases as the pH decreases and becomes a maximum when the pH fall
s below the pK(a) of the functional monomer. The mechanical properties (ult
imate elongation, ultimate strength, and toughness) improve as the amount o
f incorporated functional monomer increases. (C) 1999 John Wiley & Sons, In
c.