Effect of molecular weight on the solidification rates of poly (alpha-methylstyrene) emulsions

To research the effect of molecular weight on the solidification rates of the emulsion particles in the microencapsulation process of poly (-methyl styrene) (PAMS) hollow shells, three different kinds of PAMS with molecular weights 300, 440 and 800 kgmol-1 respectively as oil phase were further studied. In the curing process, the diameter of PAMS/FB droplets, the PAMS concentration and the evolution of FB diffusion flux under PVA and PAA solution were experimentally measured. The results show that the PAMS concentration increased slowly with the decreasing molecular weight. Especially, the summit of FB diffusion evolution flux achieved the minimum when the molecular weight of PAMS was 300 kgmol-1. Therefore, the curing time could be prolonged by reducing the molecular weight of PAMS and the diffusion rates of FB could be accordingly decreased, and during the key phase of the solidification process of double emulsions, the droplets could have enough time to adjust to obtain better sphericity.