Tailored Thermal and Mechanical Performance of Biodegradable PLA-P(VDF-TrFE) Polymer Blends

Abstract: The development of polymer blends has emerged as a strategic approach for designing multifunctional materials with enhanced tailored characteristics. Current work investigates and reports for the first time, the structure-property relationships in free-standing blend films of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) and polylactic acid (PLA), prepared to evaluate their suitability for functional applications. For this investigation, films of approximately 40 $\mu$m thick were fabricated by systematically varying the P(VDF-TrFE):PLA ratio. Thermal analysis revealed a higher PLA crystallinity at 25\% P(VDF-TrFE) content, while Fourier-transform infrared spectroscopy showed the electroactive $\beta$-phase fraction to be highest in the 50:50 composition. These findings correlated with tensile strength measurements and morphology, demonstrating that molecular ordering and phase distribution significantly influence the mechanical performance. The 25:75 blend exhibited superior mechanical strength due to enhanced PLA crystallization and polymer chain alignment. In contrast, the 50:50 blend achieved a balance between tensile modulus and electroactive phase development, marking it a promising candidate for sensors and 3D printing applications. At higher P(VDF-TrFE) content, reduced crystallinity in PLA resulted in softer, more compliant films which would be suitable for flexible electronic applications. These results establish a pathway to tune mechanical and functional properties in semicrystalline polymer blends through facile compositional control.