64375 2025 eng 4295 4309 20 63 article Wiley 1 -- -- -- Epoxy (EP) glass fiber reinforced composites (GFRCs) are extensively used in structural applications due to their excellent thermal and mechanical properties, but their inherent flammability limits fire-safe deployment. While numerous studies examine the flame retardancy of resins or individual composite systems, comprehensive studies evaluating simultaneous improvements in flame retardancy and post-fire mechanical integrity, specifically through prepreg processing, remain challenging. This study investigates the effectiveness and transferability of phosphorus-based flame retardant (FR) systems to diglycidyl ether of bisphenol A (DGEBA) and EP novolac resin matrices and their corresponding bidirectional glass fiber composites via prepregs. The FRs are chosen based on varying modes of action: ammonium polyphosphate with inorganic silicate (APP/InSi) primarily acts in the condensed phase (CP), and aluminum diethyl phosphinate with zinc hydroxystannate (AldietPO2/ZHS) is known to demonstrate both gas-phase (GP) and CP activity. Fire residues are tailored to compensate for structural defects from fire exposure. EP novolac, with higher aromaticity and cross-linking, possesses better inherent flame resistance compared to DGEBA. The novolac composites containing AldietPO2/ZHS simultaneously showed the highest retention of flexural properties after fire exposure and the best fire safety index. The experimental values of the post-fire flexural properties in the composites calibrated damage parameters in two theoretical models. Journal of Polymer Science 2642-4169 2642-4150 10.1002/pol.20250692 urn:nbn:de:kobv:b43-643752 publish 16.10.2025 false true Creative Commons - CC BY - Namensnennung 4.0 International S. Sunder Maria Jauregui Rozo H. Deshpande A. Neyer V. Papaiya Dietmar Meinel Bernhard Schartel H. Ruckdäschel eng uncontrolled Composites eng uncontrolled DGEBA eng uncontrolled Epoxy novolac eng uncontrolled Post-fire eng uncontrolled Prepregs Ingenieurbau 7 Bauwerkssicherheit 7.5 Technische Eigenschaften von Polymerwerkstoffen 8 Zerstörungsfreie Prüfung 8.5 Röntgenbildgebung Infrastruktur Fire Science Verlagsliteratur Datei für die Öffentlichkeit verfügbar ("Open Access") Wissenschaftliche Artikel der BAM Leichtbau Bundesanstalt für Materialforschung und -prüfung (BAM) https://opus4.kobv.de/opus4-bam/files/64375/25jpolmsci.pdf