Acrylic-based composite latexes containing nano-sized liquid crystalline domains

Abstract

Two-scale multicomposite (meth)acrylate latexes containing nano-sized liquid crystalline domains were synthesized in a two step (mini)emulsion polymerization using a series of methacrylate side chain liquid crystalline monomers and mixture of short chain (meth)acrylates. Detailed characterization of the composite films obtained from the latexes using a combination of DSC, TEM, polarized light microscopy, SAXS and WAXS showed that the liquid crystalline polymers had a layered structure with a 2D-organization that was not perturbed by the amorphous polymer, which on the other hand was partially intercalated between layers. This leads to a two-scale composite with enhanced mechanical properties and higher number of degrees of freedom to fine tune the mechanical properties. The effect of liquid crystalline domains on barrier properties as well as on the water resistance of the films formed from these latexes was also investigated. The persistence of crystalline order of the liquid crystalline polymer phase up to very high temperatures leads to materials with a very broad temperature range of application, improving significantly the performance with respect to other routes based on incorporation of crystalline domains via copolymerization with comb-like monomers.