Seed latex S1 consisting of styrene(St) and methyl methacrylate(MMA)

and S2 consisting of St. MMA and AA(acrylic acid)

were first prepared by batch process

then a series of St MMA-AA or MAA(methyl methacrylate) terpolymer latexes containing different amount of unsaturated acid monomers were synthesized by continuous seeded emulsion copolymerization in the absence of emulsifiers

and the composite latexes were then treated by alkali and acid subsequently at 90℃ for 3h. Particle size and morphologies were characterized by TEM using phosphotungstic acid as staning agent.The influence of swelling agent MEK(methyl methacrylate) and the initial pH value in the alkali treatment on the formation of multihollow were investigated.Experiments showed that multihollow particles

accompanied by the largest volume expansion

were observed after treatments for S1/P(St-MMA-AA) using 8.0% mole of AA in the second step monomers.At the present conditions.AA is more suitable than MAA to prepare the desired multihollow latexes particles

and seed latex S1 is more effective than S2 on the forming multihollow structure in latex particles.