Exploratory Study on the Production of Bimodal Microsuspension PVC Products in a One Pot Process

ABSTRACT An exploratory study on the possibility of developing bimodal PVC microsuspensions via the in situ generation of small particles in the presence of a large microsuspension seed is presented in order to reduce the number of process steps. The in situ nucleation step was investigated using 3 different redox initiators, and the final products were compared to the reference product made by mixing 2 seeds and copolymerizing them to increase the solid content. It was found that while none of the alternatives considered allowed to reproduce the exact PSD of the reference system, a redox system based on a combination of ammonium persulfate and Iron (II) sulfate came the closest to the reference product. It enabled us to generate well‐defined small particles in the right size range. The other systems that did not generate enough negatively charged free radicals led to poorly defined small particle populations.