Session: Polymer Division Student Poster Session: Celebrating the Diversity of Macromolecules:

Cellulose is increasingly utilized as reinforcing agent in nano-composites, due to its natural abundance, low cost and useful properties (low density, high specific surface area and elastic modulus, low coefficient of thermal expansion). Addition of cellulose nanocrystals or nanofibers to bulk polymers has been proven to enhance the mechanical and thermal properties of the resulting nanocomposites. However, the direct incorporation into thermoplastic matrixes has some negative effects on the mechanical properties due to the formation of strong agglomerates during the dispersion process. Chemical modification of the fiber surface alleviates the problem to a certain extent, but the limitation is not completely eliminated.
This presentation will describe a new approach aimed at the formation of poly(styrene) nanocomposites with homogeneous dispersion of cellulose nanocrystals and nanofibrils. The strategy is based on the radical bulk polymerization of styrene in the presence of cellulose oligomers modified with different amounts of styrene moieties. Under classical conditions (AIBN, 65°C) semi-interpenetrating networks are formed in high yields. The gels are hybrid materials, where the synthetic polymer chains are either crosslinked on the uniformly dispersed naturally-derived component or entangled through the network, see figure. The influence of the cellulose degree of substitution and polymerization conditions on the properties of the resulting poly(styrene)/cellulose nanocomposites will be discussed in detail.

Synthesized nanocomposite material, where poly(styrene) chains are crosslinked by modified cellulosic crosslink. There are present not crosslinked linear poly(styrene) chains in the material

Synthesized nanocomposite material, where poly(styrene) chains are crosslinked by modified cellulosic crosslink. There are present not crosslinked linear poly(styrene) chains in the material

Ivan Gitsov

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