Surfactant-mediated synthesis of monodisperse Poly(benzyl methacrylate)-based copolymer microspheres

Polymeric microspheres (MSs) have broad applications. Poly(benzyl methacrylate) (PBzMA) have various important applications, such as optical materials, electrochromatography, and photoresists. However, previous studies on PBzMA were on fabricating bulk polymers or nano-sized (<500 nm) spheres. In this study, by introducing a cationic surfactant, cetyltrimethylammonium bromide (CTAB), into the processing, we were the first to successfully synthesize PBzMA-based (pristine and co-polymer) highly monodisperse microspheres. In the synthesis, poly(vinyl pyrrolidone) (PVP) is used as the stabilizer to prevent particle aggregation, and cetyltrimethylammonium bromide (CTAB) is used to assist dispersion polymerization. The sizes of PBzMA-based MSs can be tuned between 1.0 and 10.0 µm with a high monodispersity by controlling the CTAB and monomer concentrations. The morphology, molecular structure, molecular weight distribution, thermal stability, and glass transition behavior of the MS samples are determined. Particularly, the glass transition temperature can be tuned continuously and smoothly between 59 °C–120 °C by adjusting the monomer ratio in the synthesis of the copolymer MSs. This study provides insights into a controlled synthesis of size- and property-tunable polymeric and copolymer MSs for broad applications.