Thermodynamics, morphology, mechanics, and thermal transport of PMMA-PLA blends

Thermodynamics controls structure, function, stability, and morphology of polymer blends. However, obtaining the precise information about their mixing thermodynamics is a challenging task, especially when dealing with complex macromolecules. This partially because delicate balance between local concentration/composition fluctuations monomer level (multibody) interactions. In this context, Kirkwood-Buff (KB) theory serves as useful tool that connects pairwise fluid structure to thermodynamics. Using larger scale molecular dynamics simulations, within framework KB theory, we investigate set technologically relevant poly(methyl methacrylate)-poly(lactic acid) blends aim elucidate underlying microscopic picture phase behavior. Consistent existing experiments, emphasize importance properly accounting for entropic contribution Gibbs free-energy change $\mathrm{\ensuremath{\Delta}}{\mathcal{G}}_{\mathrm{mix}}$ morphology. We further show how relative interaction details structures different species can control nonlinear mechanics, ductility, heat flow. Therefore, study provides guiding principle design light weight functional materials extraordinary physical properties.