1 research outputs found
Amphiphilic Block Copolymers as Stabilizers in Emulsion Polymerization: Effects of the Stabilizing Block Molecular Weight Dispersity on Stabilization Performance
Molecular weight dispersity is not
typically studied as a design
parameter of block copolymer stabilizers but is often assumed to impact
stabilization performance; low molecular weight dispersity is generally
assumed to be associated with best performance. This is the first
quantitative investigation of the effects of block copolymer molecular
weight dispersity with regards to stabilization performance in an
emulsion polymerization. Poly(styrene)-<i>b</i>-poly(acrylic
acid) block copolymers were synthesized by nitroxide-mediated radical
polymerization and employed as stabilizers in the emulsion polymerization
of styrene. The effect of the stabilizing poly(acrylic acid) block
molecular weight dispersity on stabilization behavior was studied,
independent of molecular weight and composition. Block copolymer stabilizers
were evaluated in terms of critical aggregation concentration, dispersed
phase particle size, distribution, and zeta potential. The molecular
weight dispersity of the stabilizing block affected the aggregation
number and final number of particles but displayed no negative effects
on stability or size distribution