Synthesis and characterization of hollow polymer latex particles

Latex particles with a multihollow structure were prepared by seeded emulsion polymerizatoin. Thus seed latexes Sn, consisting of styrene (St) and methyl methacrylate (MMA) copolymer, and Sa, consisting of St-MMA-AA (acrylic acid) copolymers, were first prepared, then a series of core-shell composite latexes SnCa, SnCn, SaCa and SaCn were synthesized with or without AA in the absence of emulsifiers in the second step. Final latexes were then treated by alkali and acid subsequently at 90 degrees C for 3 h. TEM observation showed that only SnCa and SaCa (prepared with AA in the second polymerization, suffix ''a'' means with AA, ''n'' means zuithout AA) produced multihollow structures in the particles, and their particle volumes increased 42% for SnCa and 23% for SaCa after the treatment in comparison with original latex particles. No hollows were observed for SnCn and SaCn particles prepared without AA and new particles were formed for the SaCn latex in the second step polymerization. (C) 1997 by John Wiley & Sons, Ltd.