Tunable Micromechanics and Morphology of Plasticized Polyhydroxyalkanoate: Roles of Structural Interactions and Crystallization in Solvents

Herein, plasticized polyhydroxyalkanoate (PHA) micromechanics are addressed through in situ morphological evolution. The innovation concerns the compatibility of droplet/fibrillar-matrix morphologies examined using relaxation time analyses via CP-MAS NMR. Enhanced interaction between PHA and in situ generated fibers was key to the improved kinetics of crazing and local strain heterogeneities. We highlight the structural changes of crystalline phases and enhanced storage modulus, induced by isothermal crystallization in soaking solvents, correlating these with the development of tensile/shear crazes and plastic deformation mechanisms. These insights enable tuning miscibility, semicrystalline nature, and strain-induced micro- and nanoscale microstructures necessary to modify PHA-based blends into reliable composites.