Aiming at improving the thermal stability and flame retardancy of polyacrylonitrile (PAN), a novel flame retardant PAN composite was prepared via a facile approach. First, lignin (LIG) and PAN were dissolved in dimethyl sulfoxide (DMSO) to form a uniform blend solution of LIG and PAN, then the solution was poured into the mould to scrape the LIG/PAN composite film. Subsequently, the flame retardant LIG/PAN composite (FR-LIG/PAN) was fabricated via phosphorylation. The structure of pure PAN, LIG, LIG/PAN and FR-LIG/PAN composite was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The thermal and combustion properties of the samples were evaluated by using thermogravimetric analysis (TGA) and cone calorimeter test (CCT). In addition, the cross section and char residue of FR-LIG/PAN composite after combustion were observed by scanning electron microscopy (SEM). Furthermore, the elemental compositions and contents of the cross section and char residue of FR-LIG/PAN composite after combustion were tested by energy-dispersive X-ray spectroscopy (EDS). The results indicated that hydroxyl group and benzene skeleton were present in LIG/PAN and the phosphorus element was successfully introduced into FR-LIG/PAN composite via phosphorylation. The amount of char residue for FR-LIG/PAN at 800 °C is more than those of pure PAN and LIG/PAN. SEM photos indicate the expansion characteristics of the char residue, and EDS results prove that the uniform distribution of elements in the cross-section of FR-LIG/PAN composite. Moreover, FR-LIG/PAN exhibits the lowest peak heat release rate (pHRR) and smoke production rate (SPR). These results demonstrated that FR-LIG/PAN had excellent flame retardancy and char forming ability. In addition, the composition of the gases evolved from pyrolysis process of FR-LIG/PAN was analyzed by thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR). The main pyrolysis products in gas phase are H₂O, CO₂ and PO•. This work proposes one facile method for preparation of practical flame retardant PAN composite.

为了提高聚丙烯腈（PAN）的热稳定性和阻燃性，通过一种简便的方法制备了一种新型的阻燃PAN复合材料。首先，将木质素（LIG）和PAN溶解在二甲基亚砜（DMSO）中以形成LIG和PAN的均匀混合溶液，然后将溶液倒入模具中以刮擦LIG / PAN复合膜。随后，通过磷酸化制备阻燃剂LIG / PAN复合材料（FR-LIG / PAN）。通过傅立叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）对纯PAN，LIG，LIG / PAN和FR-LIG / PAN复合材料的结构进行了表征。通过热重分析（TGA）和锥形量热仪测试（CCT）评估样品的热和燃烧性能。此外，通过扫描电子显微镜（SEM）观察燃烧后FR-LIG / PAN复合材料的截面和炭渣。此外，通过能量色散X射线光谱法（EDS）测试了FR-LIG / PAN复合材料燃烧后的元素组成以及横截面和炭渣的含量。结果表明，LIG / PAN中存在羟基和苯骨架，磷元素通过磷酸化成功引入了FR-LIG / PAN复合材料。FR-LIG / PAN在800°C时的残炭量比纯PAN和LIG / PAN的残渣量多。SEM照片表明了炭渣的膨胀特性，EDS结果证明了FR-LIG / PAN复合材料截面中元素的均匀分布。此外，FR-LIG / PAN的峰值放热率（pHRR）和烟雾产生率（SPR）最低。这些结果表明FR-LIG / PAN具有优异的阻燃性和炭形成能力。此外，通过热重分析和傅立叶变换红外光谱法（TG-FTIR）分析了FR-LIG / PAN热解过程中产生的气体成分。气相中的主要热解产物是H₂ O，CO ₂和PO•。这项工作提出了一种简便的方法来制备实用的阻燃PAN复合材料。