Online monitoring of vinyl chloride polymerization in a microreactor using raman spectroscopy

Abstract

A novel capillary-based microfluidic device has been designed to follow the vinyl chloride polymerization reaction. The use of a co-flow generation system enabled obtaining monodisperse vinyl chloride droplets within 200 µm in diameter, each one being considered as a polymerization reactor. During polymerization VCM droplets were visualized with a high speed camera. At the end of the reaction PVC grains were observed with a Scanning Electron Microscopy technique. Real-time non-invasive Raman measurement has been performed on stationary vinyl chloride monomer droplets and has provided values of effective reaction orders n and effective rate constants k. This microdevice allowed the investigation in difficult conditions (pressure, temperature) with a minimal amount of reagents and consequently under safe conditions.