Nanocomposites of urethanes and epoxies are useful in a variety of aerospace, electronics, sporting goods, and other applications, in part due to their high strength and low weight. The final properties of these composites rely heavily on favorable interactions between the filler and the matrix. The ability to tune the mechanical or thermal properties of these nanocomposites would further expand their utility. Our observation of significantly modified properties upon the introduction of boron cage compounds (BCCs; carboranes - closo-C2B10H12 and dodecaborane anions or boranes - [closo-B12H12]2-) and Polycyclic Aromatic Hydrocarbons (PAHs) into a variety of host polymer networks has led to a broader interest in understanding the mechanisms by which these molecules affect the host polymer matrix’s rheological, physical, and thermal properties. This presentation will review our past work characterizing the composite formed when n-hexylcarborane is blended with a polybutadiene (PBD)/polyurethane (PU) segmented copolymer (EN8), in which the glass transition temperature (Tg) of the PBD phase increases with increasing n-hexylcarborane content, but the PU phase decreases, using broadband dielectric spectroscopy (J. Non-Cryst. Solids 2013, 371-371, 6-13). However, the focus of the presentation will be the results of resent work examining the effect of incorporating free and bound polycyclic aromatic hydrocarbons, including anthracene and 2-aminoanthracene, into an ideal epoxy network (EPON 282/ EPICURE 3270), as a molecular nanofillers. When anthracene was initially physically blended into the epoxy matrix to alter the final properties, significant increases in the composite’s Tg were observed. However, the low solubility of anthracene prevented full incorporation, limiting the overall impact. As such, the epoxy resin was reacted with 2-aminoanthracene prior to incorporating anthracene to overcome solubility issues. 2-aminoanthracene chemically modifies some of the epoxy groups in the resin providing favorable interaction sites for the anthracene. The resulting nanocomposites exhibited a synergistic increase in the Tg and significantly improved thermal degradation temperatures with optimal loadings of 2-aminoanthracene and anthracene. The effects were further explored via broadband dielectric spectroscopy.

From group 4 metal mono-dicarbollide complexes to nanocomposites containing boron cage compounds

251st National Meeting (2016)

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