Enhancing Poly(3‐Hydroxybutyrate) Properties via Reactive Extrusion With Acrylic Polyol Chain Extension

ABSTRACT Poly(3‐hydroxybutyrate) (P3HB), a biodegradable polymer derived from renewable resources, holds significant promise as a sustainable alternative to conventional thermoplastics, yet its practical application is limited by brittleness, poor thermal stability, and susceptibility to chain scission during melt processing. This study addresses these challenges through a novel reactive extrusion process using a twin‐screw extruder, employing dicumyl peroxide (DCP) as a radical initiator and acrylic polyol (AP) as a chain‐extender to induce branching in P3HB. The effects of varying AP concentrations were systematically investigated, with molecular architecture, thermal stability, rheological properties, mechanical performance, and crystallinity analyzed using x‐ray diffraction, thermogravimetric analysis, rheological testing, tensile evaluation, and viscometric measurements. Results demonstrate that AP‐mediated chain extension enhances molecular weight and ductility, peaking at an optimal concentration of 5%, while thermal and oxidative degradation predominates at higher levels, reducing performance. The innovation lies in a continuous, solvent‐free, single‐step extrusion process that balances chain extension with degradation, offering a sustainable modification strategy. This approach provides critical insights into structure–property relationships, enabling the development of tailored P3HB‐based materials with improved processability and mechanical integrity for advanced applications.