Synthesis and optical properties of cocoon-like poly(methyl methacrylate) (CPM) particles in the size range of D n = 3.0–6.5 μm were studied. The synthesis of these anisotropic particles consists of two steps. The spherical poly(methyl methacrylate) (PMA) particles (D n = 2.2–5.5 μm) cross-linked by 0.2–0.8 wt% ethylene glycol dimethacrylate (EGDMA) were prepared by dispersion polymerization, using a combination of poly(vinyl pyrrolidone) (PVP) and sodium di-(2-ethylhexyl) sulfosuccinate (NaEHS) as a stabilizer in 94:840 water–methanol. Then, a suspension polymerization of 9:1 methyl methacrylate (MMA)/EGDMA in the presence of the PMA particles as seed at 85 °C in water gave non-spherical, cocoon-like CPM particles, depending on the cross-linking densities of PMA particles. The cocoon-like CPM particles (D n,c = 4.0 μm) showed the characteristic features of regular reflection, which can not be attained for conventional poly(methyl methacrylate) particles with a spherical shape. The effects of seed PMA particles with different properties on the formation of cocoon-like CPM particles and their regular reflection properties are described.
