Estimation of the interaction energy between small molecules and a silica model as an approach for predicting the interaction order between elastomers and silica

BACKGROUND: Many elastomers are reinforced with fillers to improve their mechanical properties; good reinforcement requires favorable interactions between the elastomeric chains and the surfaces of the filler particles. A useful goal is the development of computational methods that estimate these interactions, and thereby guide choices of fillers for elastomers based on the structures of the two components in nanocomposites in general. RESULTS: Experimental results available from inverse gas chromatography rank nitriles, aromatics and 1-alkenes with regard to the magnitude of favorable interactions with silica reinforcing particles. Calculations using the Gaussian 03 package of computer programs were carried out, both with and without corrections for superposition errors. For the nitrile compounds, the formation of hydrogen bonds was predicted, and the interactions of the aromatic and 1-alkene compounds with silica were shown to be dependent on electron transfer from the silica to the tested molecules. CONCLUSION: The method developed should be useful for ranking polymer-filler combinations in general with regard to the interactions known to be conducive to good reinforcement. (C) 2009 Society of Chemical Industry