Exfoliation and liquid crystal phase formation of layered double hydroxide into waterborne polyurethane coatings

Abstract

Waterborne polymer coatings based on polymer composites were prepared by using layered double hydroxides (LDH) as reinforcing inorganic particles. Starting with a model system we demonstrated the impact of the nature of the charge balancing anions of the LDH phase on the kinetics of the polymer intercalation and the film building as well as on the degree of particle dispersion. A broader scope of coating morphologies, covering particle arrangement and heterogeneities on extended length scales resulted from specific polymer-LDH particle interactions. From a combination of characterization techniques using small angle X-ray scattering, transmission electron microscopy and confocal laser scanning microscopy and by using a mixture of compatible polymers it was found that textured coatings were obtained via a liquid crystal phase of polymer stabilized LDH platelets whereas the LDH particles impact on the phase separation of incompatible polymers resulted in disperse, bicontinuous or self-stratified coatings. This novel innovative approach was found to be promising for coatings domains where a high impact resistance is needed.

Tailoring Hybrid Layered Double Hydroxides for the Development of Innovative Applications

“…Alternatively, LDH sheets may stabilize and/or provoke some polymer suborganization. This was observed in the case of waterborne polyurethane (WPU) and polyacrylamide (PAM) . In the case of WPU,[192a] some specific polymer–LDH interactions occur, resulting in the formation of textured coatings.…”

Inhibition of Steel Corrosion and Alkaline Zinc Oxide Dissolution by Dicarboxylate Bola-Amphiphiles: Self-Assembly Supersedes Host-Guest Conception

“…PES-NB, has been described previously as PES h 21 with “R” standing for an equimolar mixture of hexane-1,6-diol and 2,2-dimethyl-1,3-propanediol and “A” designating an equimolar mixture of dimer fatty acid and 1,2-cyclohexane dicarboxylic acid. Polyurethane dispersion PUR is a proprietary polymer dispersion (BASF Coatings GmbH, Muenster, Germany) that equals previously described PUR h 21 . However, here two PURs are used in a 3:1 ratio of their solid materials, that differ in the type of the diisocyanate.…”

Étude du mécanisme d'échange et de la structure des matériaux hydroxydes doubles lamellaires (HDL) par diffraction et diffusion des rayons X

“…Le processus de formation des composites HDL-polymère a également été étudié par EDXRD [15]. L'introduction de charges minérales HDL dans les polymères permet d'améliorer les propriétés mécaniques et la tenue thermique de l'ensemble, également de modifier la perméabilité au gaz du polymère.…”