Metallized thermoplastic nonwovens as integrated heating elements in fiber-reinforced composites

This study investigates the multifunctional potential of metallized polyphenylene sulfide (PPS) nonwovens integrated as electrically conductive interlayers in glass fiber-reinforced polymer (GFRP) composites. The PPS nonwovens were coated with a nickel–phosphorus layer via electroless plating and embedded between the laminate plies. The system was evaluated both as an electrothermal heating element for de-icing and as a sensing layer for non-destructive testing. For de-icing applications, icing wind tunnel tests were conducted under glaze-ice and mixed-ice conditions. The integrated heating layer enabled complete ice removal within approximately 120 s for both icing regimes, while the distributed Joule-heating mechanism ensured stable and spatially uniform surface temperatures. Furthermore, the metallized nonwovens were successfully applied as an internal thermal excitation source in shearography, allowing clear identification of impact-induced damage, including delamination. The incorporation of the metallized PPS interlayer also enhanced the mechanical performance of the GFRP composite, with flexural strength increasing from 944 MPa (reference) to approximately 1164 MPa. Dynamic mechanical analysis indicated a slight increase in glass transition temperature from 132 °C to 141 °C. These findings demonstrate that metallized thermoplastic nonwovens provide an effective approach to designing multifunctional composites for advanced engineering applications.