Energy-Saving Microwave-Assisted Synthesis of PLA for PU/PLA Hybrid Multifunctional Coatings in Drug Releas

The development of multifunctional polymeric coatings that combine biodegradability, stability, and controlled release capacity is of great importance in modern materials science. In this study, polylactic acid (PLA) was synthesized via an energy-saving microwave-assisted polycondensation route, providing an efficient and sustainable alternative to conventional synthesis methods. The obtained PLA was processed into nanofibrous mats by electrospinning and subsequently deposited onto polyurethane (PU) films to form hybrid multilayer coatings. FTIR spectroscopy indicated the absence of significant chemical interactions between PLA and PU, confirming the preservation of the individual polymer structures. DSC analysis showed the reduction in melting enthalpy which suggests effective integration of the electrospun PLA onto PU substrate and the reduced crystallinity of the hybrid PU/PLA system. SEM micrographs revealed a uniform fibrous morphology of the electrospun PLA layer, providing a coherent and stable coverage of the PU substrate. Mechanical testing of the hybrid coating revealed a tensile strength of 2.9 MPa and an elongation at break of 57%, indicating a balanced combination of strength and flexibility. Beyond pharmaceutical applications, the proposed approach demonstrates potential for environmentally friendly protective and functional coatings in biomedical and packaging technologies. The combination of microwave-assisted synthesis and electrospinning thus represents a sustainable and versatile pathway toward advanced polymer-based multifunctional coatings.