Film formation of multiphase latex particles.

Abstract

The presence of volatile organic compounds (VOCs) in conventional solvent-based polymer coatingsand their associated negative environmental impact has resulted in the increased use of waterbornealternatives. However, in many cases matching the application properties of solvent-based polymers hasproven challenging for waterborne systems due to the unique mechanism of film formation, whichrequires polymers with relatively low glass transition temperatures (Tgs). This issue can potentially beovercome by the production of latexes containing multiple phases. In this case, the presence of a high Tg¿hard phase¿ reinforces the mechanical properties in the dry state, while the presence of a low Tg ¿softphase¿ aids film formation.Although there has been a significant amount of work investigating the relationship between particlemorphology of multiphase systems and the resulting effects on the mechanical properties of the finalfilm, relatively little is known about the processes and parameters affecting the film formation processitself. This is an issue of growing importance as government mandated reductions in VOC of coatingshave become increasingly strict, making formulation of low temperature film forming systems evenharder. The main goal of this PhD thesis was to explore the influence of the morphology of multiphaselatex particles on the film formation process and the resulting mechanical properties of the final film.