Nanoplatelet Reinforcement of Cavity Cell Walls in Polymer Foams Using Carbon Dioxide Supercritical Fluid
Journal of Applied Polymer Science
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Reinforcing the cavity cell walls of polymer foams using nanoparticles can offer a new era for the property‐structure‐processing field in the development of functionalized ultra‐light components and devices manufactured from foam. When the nanoparticles are exfoliated in polymers, the viscosity substantially increases and thus mixing or foaming usually becomes almost impossible. We use CO2 supercritical fluid (CO2 SCF) for the mixing and foaming of poly(ethylene‐vinyl acetate) copolymer (EVA) with montmorillonite (MMT) nanoplatelets. The in situ evaporation of CO2 induces robust cavity cells of the EVA/MMT nanocomposite foam in a stable form of spherical shapes, which are seldom achieved by other methods. As the bubble grows and becomes stabilized in CO2 SCF, the exfoliated MMT nanoparticles are aligned at the cell walls by the Gibbs adsorption principle to minimize the surface energy at the gas–liquid interface and increase the rupture strength of the cavity walls. It is demonstrated that the developed methodology can be successfully used for foaming EVA containing high vinyl acetate (VA) content (>40%). Since EVA is too soft to construct cell walls of foam using conventional methods, the applicability of the developed methodology is extensively broadened for superior adhesion and compatibility with other materials.
Foams; Gibbs adsorption; Nanoparticles
Seo, H. W.,
Kim, Y. J.,
Kim, K. J.,
Nanoplatelet Reinforcement of Cavity Cell Walls in Polymer Foams Using Carbon Dioxide Supercritical Fluid.
Journal of Applied Polymer Science, 135(33),