Syntheses of Ethyl Cellulose Acrylate Hybrid Latex via Mini-Polymerization

Ethyl cellulose was hybridized with methyl methacrylate and butyl acrylate via mini-polymerization. The polymerization process was traced to obtain a stable reaction system. The effects of the EC content and viscosity on the monomer droplet size, the particle size and the monomer conversion were investigated. It was showed that the stability of the latex dispersion was strongly dependent of the EC content and viscosity. With investigation on ethyl cellulose series, initiator and crosslinker, the stable mini-emulsion with 10% ethyl cellulose was obtained under conditions of crosslinker and LPO as initiator.

Raman Investigation of Photopolymerization Reactions of Single Optically Levitated Microparticles

Raman spectroscopy was used to investigate polymerization reactions in a single micrometer-sized monomer droplet. An Ar+ laser levitated the microparticles and simultaneously excited the Raman scattering. The polymerization reaction was initiated by exposing the monomer droplets to the UV radiation of a mercury arc excitation lamp. The Raman spectrum of the reacting particle was investigated on-line. The results demonstrate that the combination of the technique of optical levitation and Raman spectroscopy allows nondestructive in situ measurements of single particles and is therefore very useful for the study of fundamental processes.