耐水三嗪氮-磷单分子型膨胀阻燃剂的合成及其在聚烯烃中的作用机理研究

Based on the key technical problems of low thermal stability, poor water resistance and dispersion existed in the application of intumescent flame retardant in polyolefin, we will design and synthesize a series of integrated intumescent flame retardants with the skeletal structure of triazine ring and phosphorus-carbon bonds, and use in applied fundamental research on flame retardant polyolefin. The relationships between the molecular structure of flame retardants and their properties of hydrophobicity, thermal stability and water resistance will be investigated. Explore the dose-effect and structure-effect relationships between the structure of flame retardant and the structure and properties for polyolefin, and the reasons of water resistance, high thermal stability and whether resistance for flame retardant polyolefin materials will be revealed. The effect of the substituents and cations structure in the chain of flame retardant on the flame retardant properties for polyolefin will be investigated and illuminate its effect rule. The structure, component, variation rules and chemical reaction of the degradation products in gas and condensed phase during the pyrolysis and combustion process of flame retardant polyolefin materials will be researched. The working mechanism in gas and condensed phase of the synthesized flame retardants for polyolefin materials will be revealed. The mechanical properties, water resistance and electrical insulation properties of flame retardant polyolefin materials will be comprehensive researched and evaluated. The dispersion, compatibility and water extracted resistance of flame retardant in polyolefin matrix will be analyzed. Explore the potential application of the novel flame retardant in industry. The theoretical and application guidelines will be provided for researching and development the single molecular intumescent flame retardants and flame retardant polyolefin with high performance.

基于膨胀阻燃剂在阻燃聚烯烃材料研究及应用中存在的热稳定性低、耐水与分散差等关键技术问题，本项目拟通过分子设计，构建并合成以三嗪环与磷-碳键为骨架的“三源一体”新型膨胀阻燃剂，并用于阻燃聚烯烃的应用基础研究。研究阻燃剂分子结构与其疏水、耐热、耐水解等性能的关系以及与聚烯烃结构及性能之间的量效和构效关系，揭示阻燃聚烯烃材料耐水、耐热及耐候的原因。研究阻燃剂链结构中取代基与阳离子结构对聚烯烃材料阻燃性能的影响，阐明其影响规律；研究阻燃聚烯烃材料在热降解及燃烧过程中气相和凝聚相产物的结构、组成、变化的规律及化学反应，揭示阻燃剂对聚烯烃材料在气相和凝聚相中的阻燃作用机理。通过全面研究和评价材料的力学、耐水及电绝缘性能以及阻燃剂在聚合物中的分散性、相容性及耐水抽出性能，探索一种具有工业应用潜力的新型阻燃剂，为研究开发高性能单分子膨胀阻燃剂及阻燃聚烯烃材料奠定理论基础，提供应用指导。

该项目针对传统膨胀阻燃剂阻燃效率不高、耐水性差、热稳定性低、分散性不好等关键问题，设计并制备了集酸源、碳源和气源于一体的多种单分子膨胀阻燃剂并用于聚乙烯等材料中。当添加量仅为21wt%时，材料在垂直燃烧测试时通过UL-94 V-0级，而传统膨胀阻燃剂的添加量在30wt%以上。阻燃机理表明，制备的单分子阻燃剂在凝聚相和气相都发挥了优异的阻燃作用。为解决膨胀阻燃剂的耐水问题，项目通过：（1）将三嗪结构引入到单分子膨胀阻燃剂中。例如，制备的聚二羟甲基三聚氰胺焦磷酸哌嗪酯，阻燃剂具有优异的耐水性能。当添加量为23wt%时，聚丙烯材料通过UL-94 V-0级，材料在70℃水中浸泡168h取出并烘干后，材料的失重率仅为0.67%，材料保持了优异的阻燃、力学等性能。制备的焦磷酸二三聚氰胺阻燃剂，在热塑性聚氨酯等材料中也表现了优异的阻燃、耐水及力学性能。（2）通过仿生构筑制备疏水膨胀阻燃体系。项目首先制备了疏水三嗪成炭剂，然后在超亲水的聚磷酸铵表面构筑，制备了具有粗糙结构、低表面能的类荷叶疏水结构的膨胀阻燃体系，水接触角达到了139o。阻燃剂与热塑性聚氨酯基体融为一体，耐水测试后材料截面无任何孔洞及沟槽出现。添加量为10wt%时，材料在耐水测试前后都能通过了UL-94 V-0级，材料的燃烧、力学等性能基本保持不变。（3）在阻燃剂表面进行接枝包覆。通过含硅氢键的硅烷与氢氧化镁反应，然后采用含双键的聚硅氧烷进行接枝包覆，制备疏水氢氧化镁并用于热塑性弹性体的阻燃，制备的材料表现了优异的耐水、阻燃及力学性能。项目还制备了膦酰胺类阻燃成核剂并用于聚乳酸的阻燃，当阻燃剂的添加量为2.5wt%时，材料通过了UL-94 V-0级，材料的结晶速度和结晶度都得到了提高，材料保持了优异的力学性能。通过该项目的研究，为制备高性能膨胀阻燃体系、综合性能优异的阻燃聚合物材料奠定了理论基础，提供了实验依据。