Manufacture of poly(methyl methacrylate) microspheres using membrane emulsification

Accurate control of particle size at relatively narrow polydispersity remains a key challenge in the production of synthetic polymer particles at scale. A cross-flow membrane emulsification [XME] technique was used here in the preparation of poly (methyl methacrylate) [PMMA] microspheres at a 1 – 10 L/h scale, to demonstrate its application for such a manufacturing challenge. XME technology has previously been shown to provide good control over emulsion droplet sizes with careful choice of the operating conditions. We demonstrate here that for an appropriate formulation, equivalent control can be gained for a pre-cursor emulsion in a batch suspension polymerisation process. We report here the influence of key parameters on the emulsification process; we also demonstrate the close correlation in size between the pre-cursor emulsion and the final polymer particles. Two types of polymer particle were produced in this work, a solid microsphere and an oilfilled matrix microcapsule.