Size control of aromatic polyamide hollow spheres prepared by reaction-induced phase separation

Publication date: 24 February 2017
Source:Polymer, Volume 111
Author(s): Hirofumi Nakayama, Naoto Adachi, Hironori Atarashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura
Size control of the poly (1,4-phenylene-5-hydroxyisophthalamide) hollow spheres was examined by tuning the polymerization condition, focusing on concentration, temperature and solvent. Higher concentration lowered the diameter owing to the higher degree of super-saturation for nucleation. Temperature drop during the polymerization just before the nucleation was so effective to make the diameter smaller. Moreover, the diameter was susceptive to the solubility of oligomers in the solvent, and higher content of liquid paraffin in the aromatic solvent lowered the solubility, resulting in the decrease in the diameter. Based on these results, the combination of the temperature drop and the solvent effect was the most desirable to prepare the smallest hollow spheres, and the diameter of hollow spheres could be controlled from 4.4 to 0.7 μm.

Graphical abstract

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