Multiple hydrogen-bond array reinforced cellular polymer films from colloidal crystalline assemblies of soft latex particles

Waterborne polymer films made from soft polymer latex dispersions generally suffer from deterioration of chemical resistance and physical barrier properties under high humidity conditions and upon solvent exposure. Here we demonstrate the fabrication of robust polyhedral cellular polymer films from poly(methyl methacrylate-co-butyl acrylate) latexes, which were made by emulsion polymerization using a 2-ureido-4-pyrimidinone (UPy) functional methacrylate comonomer. Multiple hydrogen bond (MHB) arrays provided by UPy groups arrest the film formation process thereby creating a cellular reinforcement. The cellular polymer films exhibit impressive physical and mechanical properties. Upon solvent exposure, the films show colloidal crystalline-type Bragg diffraction features and do not suffer excessive and deteriorative uptake of water and, more remarkably, can absorb high amounts of organic solvents, thereby turning into an organogel with preservation of shape, up to a 14-fold volumetric swelling ratio of the polymer films in case of chloroform