Phase Separation Kinetics of a Polymer Blend Modified by Random and Block Copolymer Additives

TitlePhase Separation Kinetics of a Polymer Blend Modified by Random and Block Copolymer Additives
Publication TypeJournal Article
Year of Publication2001
AuthorsBarham, Bethany, Fosser Kari, Voge Gretchen, Waldow Dean, and Halasa Adel
JournalMacromolecules
Volume34
Issue3
Pagination514-521
AbstractThe phase sepn. behavior of blends of polystyrene and polybutadiene modified by copolymer additives was studied using light scattering techniques. Block and random copolymers with equal styrene and butadiene content and a random copolymer with unequal monomer compn. were used as additives at a concn. of 2.5%. The sym. additives lowered the phase boundary with increasing concn. while the asym. additive destabilized the phase boundary. The data demonstrate a slowing of the kinetics with the addn. of any of the copolymers. In comparison to the binary blend, droplet sizes in the early stage were smaller with added sym. block copolymer and larger with added asym. random copolymer. Scaling anal. of the intermediate stage kinetics showed some deviations relative to binary scaling results. Deviations from Porod's law indicate that modifications to the interfacial boundary are most notable for the asym. random copolymer. Self-similarity was seen to hold for all of the systems.