Synergistic engineering of poly(3-hydroxybutyrate) architecture and stereomicrostructure achieves enhanced material properties

Abstract

Chemically engineering stereomicrostructures of biodegrdable poly(3-hydroxybutyrate) (P3HB) has shown to be an effective approach to largely modulate its properties towards mono-material product design, but whether coupling of this method with engineering P3HB architectures could yield an even more effective strategy has yet to be demonstrated. Here, through the stereochemically and architecturally controlled polymerization, four-arm star-shaped P3HBs consisting of stereo-perfect isotactic, iso-rich, and syndio-rich stereomicrostructures, as well as their linear counterparts of comparable molar mass as controls, have been synthesized. Comprehensive and comparative characterization studies have uncovered various degrees of impacts of the P3HB architecture on thermal transitions and crystallization behaviors, mechanical performance, as well as rheological and gas barrier properties. In particular, coupling of both stereomicrostructure and architecture engineering approaches has produced synergistically enhanced effects on the overall materials properties, providing a more powerful strategy to design mono-materials with vastly different properties without changing their chemical composition.