Agglomeration Behavior and Kinetics of Polybutadiene Particles in the Polymer Agglomeration Process

Abstract

The agglomeration of polybutadiene latex (PBL) is a complex process influenced by numerous factors. Up to now, the change of particle size of agglomerated PBL with time under varying conditions remains unclear, and the agglomeration kinetic model of PBL has not been proposed. In this study, the influence of the process parameters on the particle size of agglomerated PBL with time was studied, including the amount of agglomerating agent, temperature, stirring rate, and solid content of PBL. According to the particle size evolution of agglomerated PBL, the agglomeration process of PBL is divided into two stages, including the dispersion of the agglomerating agent and its adsorption and coalescence with PBL (stage I), followed by the shrinkage of agglomerated PBL particles (stage II). It was found that the process of stage I can be accelerated significantly by increasing the amount of agglomerating agent and agglomeration temperature during PBL agglomeration, thereby reducing the total agglomeration time. The mean particle size of agglomerated PBL was also reduced when the agglomeration process reached stability. With the increase of stirring rate, the time required for agglomeration of PBL and the mean particle size of agglomerated PBL decrease. The higher the solid content of pre-agglomerate PBL, the shorter the time for PBL to complete the agglomeration, but it has no obvious effect on the mean particle size of agglomerated PBL. Based on the experimental results, on the one hand, a novel method for expressing the particle size shrinkage of agglomerated PBL was developed. This analysis was based on the change of mean particle size of agglomerated PBL with time. On the other hand, the Boltzmann equation was used to fit the agglomeration kinetics of the whole process of PBL agglomeration. The results showed that the predicted values were in good agreement with the experimental values when PBL was agglomerated under different process parameters. Knowledge obtained from this study will provide insight into the influence of process parameters on the particle size of agglomerated PBL over time, and the establishment of kinetic models can help the industrial development of PBL agglomeration technology.