Consequences of Melt Memory and Thermal Degradation for Poly(3-hydroxybutyrate -co -4-hydroxybutyrate) Crystallization
Year: 2026
Type: article
Abstract: Crystallization in poly(3-hydroxybutyrate- co -4-hydroxybutyrate) (P(3HB- co -4HB)) is strongly influenced by the thermal history. Additive-free P(3HB- co -5% 4HB) was biosynthesized, and melt memory domains were identified from DSC crystallization measurements after processing for 3 min at temperatures between 152 and 212 °C. A broad self-nucleation domain (∼20 °C) was confirmed by polarized optical microscopy, whereas complete melt memory erasure led to sparse nucleation and slow crystallization. Thermal degradation, already present at low processing temperatures, substantially reduced the molecular weight, which was shown to affect spherulite growth rates and overall crystallization behavior. When melt memory was evaluated after thermal history removal (3 min at T DI ) and recrystallization, the self-nucleation domain narrowed (∼10 °C). Increasing T DI further weakened memory due to degradation-induced molecular weight reduction. These results demonstrate that meaningful crystallization studies of P(3HB- co -4HB) require careful optimization of processing temperatures to balance melt memory effects with molecular weight retention within the narrow thermal processing window of this copolymer.
Source: Macromolecules
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: Fundamental development of continuous flow technology toward photomediated polymerization of diverse building blocks, Elucidating the structure-property relations and crystallization kinetics of sustainable polyhydroxyalkanoate biopolymers. Production and analysis of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)., Next-Generation Photomediated Polymer Production With Innovative Flow Reactor Technology (Nex-Gen-Photo-Flow), G6075980508
OpenAlex ID: W7125821445