Nanocomposites of Hyperbranched and Dendritic Polymeric Systems and Nanoclays
George Simon, Debdatta Ratna, Ole Becker, Russell Varley
School of Physics and Materials Engineering, Monash University
Australia

Keywords: nanocomposites, dendrimers, hyperbranched polymers

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Nanocomposites represent an exciting, much-studied area of polymer science due to the ability to manipulate polymer properties using relatively small amounts (less than 5 wt%) of nanoclays. These layered silicates have platelets of layer thickness of 1 nm, and high aspect ratios. Much work has been done in thermoplastic and thermosetting systems, targeting properties such as increased modulus, strength, fire resistance, gas and moisture barrier, with little change to rheology. The nanoclays are typically surface treated, often with alkyl ammonium units, to provide appropriate conditions for the polymer molecules to reptate into the clay galleries.

Much less has been done with dendritic or hyperbranched materials, polymer molecules with a highly branched, tree-like structure. these materials are expected to move into the interlayers readily, given their compact, globular shape – provided the thermodynamic forces are suitable. In this work we examine three main dendritic systems and their interaction and properties with organo-ion treated nanoclays. These include looking at the intercalatability of perfect dendritic polymers and hyperbranched aliphatic polyesters, as a function of generation. This will be largely investigated by x-ray diffraction and thermal analysis. Work describing the use of epoxy-functionalised hyperbranched polymers, and the affect of their inclusion into crosslinked epoxy systems will also be discussed. The efficacy of these materials in toughening of brittle thermoset resins will thus be investigated, as will the production of ternary epoxy systems (epoxy + nanoclay + hyperbranched polymer).