Effect of molecular weight on the morphology of polystyrene/poly(methyl methacrylate) composite particles prepared by the solvent evaporation method.
The effect of molecular weight on the morphology of polystyrene (PS)/poly(methyl methacrylate) (PMMA) composite particles was investigated. PS/PMMA composite particles with different molecular weights (M*=MwPS+MwPMMA)/2 approximately 2x10(4)-1x10(6) g.mol(-1)) were prepared by the release of toluene (T) from PS/PMMA/T (1/1/24, w/w/w) droplets dispersed in an aqueous solution of polyoxyethylene nonylphenyl ether nonionic surfactant (Emulgen 911). As T evaporated, the spherical droplets phase separated, resulting in snowmanlike composite particles with Janus morphology. The nonspherical shape was closely related to the morphology, which depended on M*. The interfacial tension between the phase-separated PS and PMMA phases increased with an increase in M*, and this would allow the formation of the snowmanlike shape to decrease the interfacial area between the PS and the PMMA phases.
Graduate School of Engineering, Kobe University, Kobe, Japan.
Takuya
T
Tanaka
Reiko
R
Nakatsuru
Yoshimi
Y
Kagari
Naohiko
N
Saito
Masayoshi
M
Okubo