Supramolecular association of acid terminated polydimethylsiloxanes. 3. Viscosimetric study

Due to dimerization through hydrogen bonding of chain ends, benzoic acid terminated polydimethylsiloxane 1 forms a supramolecular polymer in low polarity solvents. Viscosity measurements in dichloromethane, carbon tetrachloride and hexane have been performed. In order to analyze the results, a covalent model 6 of the supramolecular polymer has been synthesized and its viscosimetric parameters (Mark-Houwink and Huggins constants) have been measured. It is experimentally shown that, in dilute solution, the viscosity of a supramolecular polymer can be satisfactorily evaluated if viscosimetric parameters of a suitable covalent model are known.