Advanced Polyurea/Polyurethane Coatings for Mechanical Reinforcement, Biological Shielding, and Dielectric Enhancement of Aged Wood

ABSTRACT The recovery of aged wooden structures and the prevention of premature degradation in new ones are key challenges in materials science, especially within electrical distribution systems. Polyurea/polyurethane‐based polymer coatings provide an effective strategy for enhancing mechanical performance, thermal stability, and biological protection. Wood samples from different species were coated with polyurethane, polyurea and subjected to physicochemical, mechanical, thermal, and biological characterization. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the high conversion of isocyanate groups, demonstrating efficient polymerization under the applied coating conditions. Flexural testing indicated a notable reduction in deflection for polyurea and hybrid coatings (33%–37%), whereas polyurethane produced more modest improvements (23%). Polyurea displayed superior mechanical performance, preserving coating integrity even after wood fracture, while polyurethane exhibited the best flame‐retardant behavior. Microbiological tests emphasized the susceptibility of uncoated wood to fungal and bacterial attack. Polyurea functioned as an effective physical barrier, markedly reducing microbial colonization without relying on intrinsic biocidal properties. The results indicate that polyurea is a promising coating for extending the service life of wooden crossbeams in electrical distribution networks, and the incorporation of flame retardants can further improve fire safety. This study highlights the potential of advanced polymer coatings as scalable, sustainable solutions for maintaining and protecting electrical infrastructure.