Biodegradable supramolecular composites of poly(e-caprolactone) and low-molecular-weight organic gelators

When a homogeneous hot liquid of poly(e-caprolactone) (PCL) with (R)-12-hydroxystearic acid (HSA) or N-carbobenzyloxy-L-isoleucylaminooctadecane (CIA) was gradually cooled to room temperature, the mixture became gelatinous material and then solidified to give a PCL/HSA or PCL/CIA composite. The rheological measurements of the mixtures of PCL with HSA and CIA revealed that the organogels are formed at around 70-50 degrees C and 100-73 degrees C during the cooling process, respectively. Furthermore, the formation of supramolecular fibrillar networks was confirmed by the microscopic and differential scanning calorimetric analyses. The tensile moduli of both the composites were improved by the addition of CIA and HSA. Both the composites showed so high biodegradability as PCL. The fibrillar networks of the composites were also regenerated during the repeated cooling process from the isotropic liquid. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012