Dynamic Modeling of the Particle Packing and Deformation Stages of Film Formation for Latex Blends and Structured Latex Particles

摘要

Latex film formation involves the dynamic packing, deformation and coalescence of particles from their originally dispersed state through to a consolidated material. Each of these processes involves movement and/or flow of particles and/or polymer. In the event of latex blends or structured composite particles, there are two or more polymer phases to consider. We have been working towards a comprehensive dynamic model of the entire filming process. This discussion will focus on the dynamics during the particle packing and deformation portions of this process for systems that involve two polymer phases. In the modeling, we consider Brownian motion of many thousands of particles interacting and compacting during the dynamic loss of water from the film. Interparticle forces (via DLVO theory) influence the particle-particle structure that builds during the computations for latex blends with different particle sizes and size distributions. The spatial distribution of each material in the final packed bed is a result of the competing events that transpire over the course of the simulation. Subsequent to the packing stage, we have modeled the 3D dynamic deformation of the particle packs that result from the first stage. The viscoelastic modulus of each component in the blend is considered, as well as the effect of hydroplasticization.