Temperature influence on MBS latex aggregate morphology

This paper aims to better understand the impact of process conditions on the morphological properties of MBS (Methacrylate Butadiene Styrene) core-shell latex aggregates during an aggregation process. Laboratory scale experiments were performed in a stirred reactor following a standard industrial procedure including a first destabilization step by adding acid at a moderate temperature followed by a second heating step. The size and shape distribution of the aggregates as well as their fractal dimension were measured by laser diffraction and image analysis. The experimental data were analyzed in terms of number and volume distributions to obtain information on the entire population, from primary nanoparticles to aggregates several orders of magnitude larger. The main new finding of this work concerns the influence of the aggregation temperature on the size, shape and structure of latex aggregates. Indeed, the closer the temperature is to the glass transition of the MBS shell polymer, the better the agglomeration and the aggregates formed tend to be larger and more circular.