Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE This study demonstrates how the choice of polymer matrix governs the properties of sustainable composites. In talc-reinforced PLA/PBS blends, a PLA-rich matrix yields a stiff, easy-flowing material for complex shapes. A PBS-rich matrix creates a tough, heat-resistant material for durable parts. This matrix selection provides a clear design rule for tailoring bio-based polymers in injection molding.

ABSTRACT
This study develops a material selection framework for injection molding by systematically comparing two talc-reinforced bio-compounds with opposing compositional dominance. The compounds h-PBS-T15 and h-PLA-T15 (15 wt% talc) were comprehensively characterized via mechanical testing, thermal analysis, rheology, and FT-IR. The results quantitatively demonstrate that the dominant polymer matrix dictates the final performance profile by governing the role of talc. The PBS-dominated compound (h-PBS-T15) exhibited superior toughness (impact strength 63.4 kJ/m2) and a higher heat deflection temperature (67.3°C). The PLA-dominated compound (h-PLA-T15) provided a better stiffness-flow balance (tensile modulus 341 MPa) and, critically, achieved a Vicat softening temperature (VST) of 105.7°C, matching the PBS-based system due to talc's reinforcement. Both materials showed excellent injection molding processability. This work provides a quantitative design rule: select a PLA-rich matrix for stiffness and flowability in complex, rigid parts, or a PBS-rich matrix for toughness and heat resistance in durable, impact-resistant components.