ABSTRACT In order to develop an environmentally benign flame retardant for unsaturated polyester resins (UPR), an effective intumescent flame retardant architecture based on chitosan (CH) and ammonium polyphosphate (APP) was successfully deposited on the surface of diatomite particles by Layer-by-layer (LbL) assembly. With nine bilayers of CH/APP coating, UPR/9BL@Dia composites exhibiting LOI value of 25.7% and V-0 rating. Cone calorimetry test reveals that 9BL@Dia reduces the peak heat release rate and total heat release of UPR by 40.8% and 18.1%, respectively. Due to the unique morphology of 9BL@Dia particles, UPR/9BL@Dia composites achieves greater thermal stability and higher char yields than pure UPR. Based on the investigation of the gas and condensed phase, flame retardant mechanism of nBL@Dia was proposed as that APP/CH was heated to form phosphate esters, and then combined with diatomite to form a more stable and firm carbon structure, which can improve the fire safety of UPR composites.

中文翻译：

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基于壳聚糖和聚磷酸铵的层层组装硅藻土提高不饱和聚酯树脂的防火安全性

摘要 为了开发一种环境友好的不饱和聚酯树脂阻燃剂（UPR），一种有效的基于壳聚糖（CH）和多磷酸铵（APP）的膨胀型阻燃剂结构通过逐层沉积成功地沉积在硅藻土颗粒表面。层 (LbL) 组件。具有九层 CH/APP 涂层的 UPR/9BL@Dia 复合材料表现出 25.7% 的 LOI 值和 V-0 等级。锥形量热测试表明，9BL@Dia 使 UPR 的峰值放热率和总放热率分别降低了 40.8% 和 18.1%。由于 9BL@Dia 颗粒的独特形态，UPR/9BL@Dia 复合材料比纯 UPR 具有更高的热稳定性和更高的成炭率。基于对气相和凝相的研究，