Influence of Solvent/Polymer Interaction on Miscibility of PMMA/PCL Blend: Thermal Analysis Approach

The aim of the present work is to probe the influence of solvent on miscibility behavior of a blend of poly(e-caprolactone) (PCL)/Poly (methyl methacrylate) (PMMA). PMMA/PCL blend with mass ratio of 50:50 is employed to prepare the solutions of three different solvents including tetrahydrofuran, toluene and dichloromethane. At the equilibrium situation, the separated phases are cast by film multi-applicator for solvent evaporation and analyzed using thermal analysis (DSC and DMA) approaches. According to the results, the solvent is able to change the saturation value of PCL into the PMMA-rich phase by changing the free energy of the mixture. Through the PCL melting enthalpy as well as the glass transition of PMMA, the capability of PMMA-rich phase for dissolving the PCL and vice versa is investigated. To realize the influence of solvent for these variations, Hansen solubility parameter of components is considered to analyze. It is shown that glass transition of PMMA can be reduced to low values of about 50 °C as a result of solvent-induced miscibility with PCL at room temperature which is not easily achievable by other processes.