Assessment of the structures contribution (crystalline and mesophases) and mechanical properties of polycaprolactone/pluronic blends.

Films of biodegradable blends of polycaprolactone (PCL) and Pluronics F68 and F127 were manufactured by an industrial thermo-mechanical process to be applied as potential delivery systems. The effects of Pluronics on the structure (mesophase organization), and thermal and mechanical properties of polycaprolactone were investigated using differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), polarized optical microscopy (POM) and tensile mechanical tests. The addition of Pluronics affected the crystallization process by changing the relative amounts of crystalline, amorphous, and meso- (condis + plastic) phases. The melting transition and XRD profiles were deconvoluted to assess the individual contribution of the different crystal morphologies. Furthermore, it was found that the mechanical properties of the blends depended on the ratio and type of Pluronic. Thus, Pluronic F127 showed a larger mesophase content than its F68 counterpart with PCL and blends with enhanced ductility. [Display omitted] • Pluronic influences mesophase organization, thermal and mechanical properties of PCL. • The presence of condis and plastic mesophases in PCL/Pluronic blends was corroborated. • SAXS, DSC and XRD techniques allowed the evaluation of the crystallites organization. • Pluronic F127 demonstrates a superior compatibility with PCL against Pluronic F68. [ABSTRACT FROM AUTHOR]