(275b) Mechanical Reinforcement and Nanoparticle Dispersion of Hydrogen Bonded Supramolecular Polymer-Silica Nanocomposites

We have prepared supramolecular polymer nanocomposites using both poly(butyl acrylate) hydrogen bonded sidechain supramolecular polymers and poly(ε-caprolactone) linear supramolecular polymers blended with complementary hydrogen bond functionalized silica nanofillers.  The use of complementary hydrogen bonding groups prevents hydrogen bonding between nanoparticles while allowing the nanoparticles to intimately participate in the supramolecular polymer network.  Mechanical properties, including stress-strain behavior, dynamic modulus, and creep were investigated over a range of temperatures for various nanoparticle loadings and nanoparticle surface functionality levels.  The effect on crystallinity for poly(caprolactone) supramolecular polymers was used to explain trends in reinforcement behavior for the semi-crystalline supramolecular polymer nanocomposites.  Additional comparison of nanoparticle dispersion and nanocomposite reinforcement in materials made with self-complementary and complementary nanofillers provides a more complete understanding of these hydrogen bonded nanocomposite materials.  In particular, significant improvement in the mechanical properties and nanoparticle dispersion was found for nanoparticles with complementary, rather than self-complementary, hydrogen bonding interactions.  Finally, these nanocomposites’ self-healing behavior was also investigated.