Layer-wise halogen-free flame-retardant modification of polypropylene fabric laminates: Fire response and tensile performance
Next Materials, cilt.13, 2026 (ESCI, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 13
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.nxmate.2026.103843
- Dergi Adı: Next Materials
- Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus
- Anahtar Kelimeler: Halogen-free flame-retardant, Layer architecture, Limiting oxygen index, Polypropylene fabric, Thermoplastic laminate, Zinc borate
- Bursa Uludağ Üniversitesi Adresli: Evet
Özet
Polypropylene (PP) fabric laminates were modified with three halogen-free inorganic flame-retardant (FR) systems—zinc borate, a zinc phosphate/zinc oxide compound, and high-purity magnesium hydroxide—by placing the additives at selected interfaces before heat pressing. The study was designed as a layer-position screening experiment rather than a concentration-optimization study. Eight PP fabric plies were consolidated by thermal pressing, and the influence of FR chemistry and through-thickness position was evaluated using tensile testing, limiting oxygen index (LOI), qualitative horizontal flame-exposure screening, and SEM–EDS. The neat PP laminate showed an LOI of 16.0%. Zinc borate produced the largest increase, reaching 17.1% when located at the two central interfaces, whereas the corresponding zinc phosphate/zinc oxide and magnesium hydroxide configurations returned to 16.0%. Tensile response was strongly architecture-dependent: the control strength was 24.192 MPa and zinc-borate A4–A5 retained 24.028 MPa (99.3% of the control), while several zinc phosphate/zinc oxide and magnesium hydroxide configurations showed substantially lower strengths. EDS detected the expected additive-specific elements in the analyzed regions, confirming local incorporation but not bulk homogeneity. The results show that spatial placement can influence the balance between fire response and tensile performance, but the modest LOI changes remain below the oxygen concentration of air and therefore do not constitute a flame-retardant classification. The findings are best interpreted as a process-architecture screening study that identifies promising layer configurations for subsequent optimization with controlled additive loading and standardized fire and thermal characterization.