Poly(styrene-methyl methacrylate) microcapsules prepared by ultrasonically initiated miniemulsion polymerization phase separation method

Abstract

Ultrasonically initiated miniemulsion polymerization phase separation was employed to prepare poly(styrene-methyl methacrylate) (P(St-co-MMA)) microcapsules. The results of a thermal analysis revealed that it was difficult to form a microcapsule structure from neat styrene (St). However, MMA shows improved interface conditions due to its higher hydrophilicity than St. Therefore, it was easier to form hollow structures because the polymer microcapsules had a lower interface free energy per unit area. The results of dynamic light scattering (DLS), transmission electron microscopy (TEM) and atomic force microscopy (AFM) showed that P(St-co-MMA) microcapsules were uniform in size (about 100 nm in diameter and 20–25 nm in shell thickness).