Phase behavior of blends of poly(epsilon-caprolactone) and a modified montmorillonite-poly(epsilon-caprolactone) nanocomposite

摘要

Blends between high-molecular weight poly(epsilon-caprolactone) (PCL) and an intercalated nanocomposite of poly(epsilon-caprolactone)-organophilic montmorillonite (OMONT), containing 30% by weight of the nanofiller (NPCL30) have been investigated. Such blends have been shown to have much improved mechanical properties with respect to the parent polymer. The detailed phase behavior, crystallization kinetics, and morphology of neat PCL and of blends containing 2, 9, and 15% by weight of OMONT have been studied by using differential scanning calorimetry (DSC). The thermal properties and the overall crystallization rate of pure PCL are strongly influenced by the presence of the montmorillonite nanoparticles.The study of the solid-state dynamic-mechanical properties revealed an enhancement of the storage modulus in particular above T-g and upon increasing the clay content. The enhancement of the modulus can be attributed to confined orientation of the polymer chains among the silicate galleries (intercalation). This is confirmed by the appearance in the sample with the highest clay content, of a second T-g peak at higher temperature indicative of a less mobile amorphous fraction.