A detailed investigation of the co-polymerization kinetics and particle formation of nanoscopical poly(EGDMA-co-MAA) by miniemulsion polymerization

POLY 474

Marc Herold, mhe@igb.fhg.de, Eike Müller, eike.mueller@igb.fhg.de, Melanie Dettling, Achim Weber, achim.weber@igb.fraunhofer.de, Herwig Brunner, and Günter E. M. Tovar, gto@igb.fhg.de. Department of Biomimetic Surfaces, Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstr. 12, Stuttgart, 70569, Germany
Miniemulsion polymerization has gained great importance in molecular imprinting. Nevertheless copolymerization kinetics and particle evolution in these systems are only poorly understood. We monitored the particle size, zeta-potential, copolymer composition, particle surface area and the monomer conversion for the copolymerization of methacrylic acid and ethytenglycol dimethacrylate. The polymerization was thermaly initiated by an azo-initiator at 80°C. The results for these parameters showed that the methacrylic acid was mostly copolymerized in the second half of the processing and the formation of pores incresed after the first 10 minutes of polymerization. This leads to a copolymerization model that consists of a short nucleation periode in the monomer droplet and a following diffiusion periode of methacrylic acid from the aqueous phase into the growing polymer particle.