Journal of Polymer Science Part B: Polymer Physics, Vol.36, No.12, 2191-2196, 1998
Particulate growth in phase-separated polymer blends
Particle coarsening was investigated in polymer blends containing a minor phase volume of 23% produced by compositional quenching. The scaling exponents for three binary blends (polystyrene/polybutadiene, polystyrene/polyisoprene, and polystyrene/S-B random copolymer) were in reasonable agreement with the expected value of 0.33. The scaling exponent for a ternary blend containing an amphiphile (polystyrene/polybutadiene/S-B block copolymer) was substantially lower at 0.14. The particle size distributions for all the blends were broader than the self-similar distribution expected for Ostwald ripening and became increasingly broad with time. These distributions fit a two parameter coalescence model in which the probability of coalescence is proportional to the particle diameter. However, Ostwald ripening appears to make some contribution, particularly at early times.
Keywords:DROPLET SPINODAL DECOMPOSITION;PARTICLE DIFFUSION PROBLEM;COARSENING MECHANISMS;BINARY-MIXTURES;VOLUME FRACTION;KINETICS;MORPHOLOGY