Solid-state compounding of immiscible PCL-PEO blend powders for molding processes.

Solid-state milling is a promising ecologically friendly method for fabricating polymeric blend and composite powder raw materials for several subsequent manufacturing processes. Biodegradable polymers, blends, and composites are expected to find extensive use by industry due to their environmental friendliness and acceptable mechanical and thermal properties for several applications. Poly-ε-caprolactone (PCL), poly-ethylene-oxide (PEO), and their blends have attracted so much attention to replace commodity polymers in future applications. Therefore, in the current research, bulk compounding of PCL-PEO blends with various compositions using solid-state cryomilling was investigated. Structural, mechanical, thermal, and hydrophilicity properties were examined on samples obtained by compression molding to explore the capabilities of the milling process for various applications. Morphology of the blends was explored by scanning electron microscopy (SEM), which showed a clear phase separation in blends after heating. Dispersed as well as co-continuous morphologies were achieved by varying composition. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) of the blends indicated insignificant amorphization by milling. Tensile strength, modulus, and percentage elongation at break of the blends demonstrated significant variations due to processing parameters.