随着木塑复合材料在建材、室内装饰等应用领域的不断扩大，其防火安全性越来越受到重视。本项目以构筑木塑复合材料的阻燃体系为出发点，通过研究纳米晶态纤维素（NCC）、聚磷酸铵（APP）与纳米二氧化硅（nano-SiO2）聚电解质的合成工艺和结构特性，定向自组装NCC/APP/SiO2复合聚电解质（PECs），阐述聚电解质结构特征、温度、pH值对PECs超分子结构和形成机制的影响规律，通过调控静电吸附、范德华力、氢键等驱动力，使得APP置于分子结构的芯层，获得均一稳定、界面性能优良的定向网络结构；然后将此PECs应用于木塑复合材料，深入研究木塑复合材料热解燃烧过程中，PECs三组分催化木质纤维酯化、脱水交联反应，促进均匀稳定炭层的形成过程，阐述NCC、APP、纳米SiO2的阻燃协同机制。本项目的研究成果将丰富木塑复合材料阻燃技术。同时，也为NCC在绿色阻燃剂合成领域的应用提供理论依据和技术支撑。

Flammability is one of the important parameters that often limits the application of wood plastic composites (WPC) to constructions and interior decoration. Recently, the synergistic effect between nano-SiO2 and ammonium polyphosphate (APP) in polymer and composites has been extensively investigated. However, the synergistic of APP/nano-SiO2 has some limits in application of flame retardant WPC due to the bulk density and surface area. On the other hand, nanocrystalline cellulose (NCC) is considered as an excellent template and polyelectrolyte material due to the abundant hydroxyl groups and sulfonic acid group. The preparation of polyelectrolyte composites (PECs) of NCC/APP/nano-SiO2 using oriented self-assembly technique is proposed in this project. This project will be focus on (1) the characteristics and formation of polyelectrolyte of NCC, APP, and nano-SiO2, (2) the formation mechanism of PECs using oriented self-assembly technique affected by temperature, pH values, and polyelectrolyte of NCC, APP, and nano-SiO2 respectively, and (3) the application and flame retardant mechanism of PECs of NCC/APP/nano-SiO2 in WPC. The conclusions from this project would promote the theory and technology development in the fields of flame retardancy of WPCs by utilization of PECs of NCC/APP/nano-SiO2. Moreover, it can promote the application of NCC in chemical synthesis field of green flame retardant.