Microstructure and thermomechanical properties of Poly(e-caprolactone)/polyhedral oligomeric silsesquioxane (POSS) nanocomposites

Abstract

In this study, POSS was modified to have a sulfonic acid moiety and the sulfonated POSS(sPOSS) was blended with poly(e-caprolactone) by solution casting using a chloroform as a solvent. WAXD revealed that the POSS formed a nanocrystal in the PCL/sPOSS hybrids. FT-IR analysis exhibited that the there exists a strong hydrogen bonded interactions between sulfonic acid group of sPOSS and carbonyl oxygen of the PCL. Such a strong interactions between POSS-POSS as well as sPOSS-PCL caused a formation of physical crosslinking in the PCL/sPOSS hybrids, which was manifested by a presence of rubbery plateau above its melting temperature. The physical crosslink induced increase in storage modulus of the hybrids and a decrease in melting points and degree of crystallinity of the PCL phase. It was also noted that heat triggered shape memory effects were observed for the PCL/sPOSS hybrids.