Sustainable high performance basalt fiber reinforced composite with zero flammability

The transition to lightweight, fire-safe, and sustainable materials in automotive demands composites that simultaneously have mechanical performance, thermal stability, and zero flammability, requirements that are rarely met by conventional fiber-reinforced plastics composites. This study develops a high-performance, non-flammable polyamide 6,6 hybrid composite by integrating silane-treated basalt fiber, a non-halogenated flame-retardant (FR) and lignin-derived biocarbon as co-flame retardant synergist to engineer a densely constrained polymer-filler network. Basalt fibers provided stiffness enhancement, while silane modification significantly improved the fiber–matrix interface, resulting in improved tensile and flexural moduli of 9170 MPa and 9436 MPa, respectively. Incorporation of FR and porous lignin biocarbon generated an intumescent, carbon-rich protective layer that increased thermal stability (T_max = 445 °C, residue = 32.3%) and heat deflection temperature (240.4 °C). The hybrid architecture suppressed melt mobility and segmental relaxation, as evidenced by the damping factor, high storage modulus, low thermal expansion (31.47 µm/m·°C), a 60% reduction relative to neat PA66. The analysis of viscoelastic behaviour through modelling showed a high degree of entanglement between PA6,6 and reinforcement. Critically, the hybrid composite achieved a UL-94 V-0 rating with zero horizontal burn rate. The sustainable hybrid composite with a sustainable content of 35% directly addresses emerging automotive need for lightweight and fire-safe components such as battery housings, under-the-hood modules, and structural enclosures.

汽车领域向轻量化、防火安全且可持续材料转型的过程中，亟需同时具备力学性能、热稳定性与零易燃性的复合材料，而传统纤维增强塑料复合材料极少能满足此类要求。本研究通过将硅烷改性玄武岩纤维、无卤阻燃剂（FR）与木质素衍生生物炭作为复配阻燃协效剂进行复合，制备出高性能不燃聚酰胺66（PA66）混杂复合材料，构建了致密受限的聚合物-填料网络结构。玄武岩纤维可提升材料刚度，而硅烷改性显著优化了纤维-基体界面性能，使复合材料的拉伸模量与弯曲模量分别达到9170 MPa与9436 MPa。引入阻燃剂与多孔木质素生物炭后，体系可形成膨胀型富碳保护层，提升了材料的热稳定性（热失重峰值温度T_max=445℃，残炭率32.3%）与热变形温度（240.4℃）。该混杂结构可抑制熔体流动性与分子链段松弛，具体表现为阻尼因子提升、储能模量较高、热膨胀系数较低（31.47 μm/m·℃），相较于纯PA66降低了60%。通过建模对黏弹性行为的分析表明，PA66与增强体之间存在高度的缠结作用。尤为关键的是，该混杂复合材料达到了UL-94 V-0阻燃等级，且水平燃烧速率为零。该可持续混杂复合材料的可持续成分占比达35%，可直接满足汽车领域对轻量化防火安全部件的新兴需求，例如电池壳体、发动机舱模块与结构护罩等。