具有阻燃功能性新型离子液体的设计合成及阻燃机理研究

As we know, when most inorganic flame retardants are used in polymer matrix, the mechanical properties of flame retardant material are deteriorated. How to enhance the flame retardant efficiency and low inorganic flame retardant dosage? This is the key issue to endow polymer with flame retardance and simutaneously keep its mechanical properties. . Ionic liquids (ILs) have been used in many areas, such as organic synthesis, biocatalysis, separation process, elctrochemisty,and polymer chemisty, etc.due to their negligible vapour pressure, non-flammability, high thermal stability and easily tunable physical and chemical properties. Recently, some ILs have been used as plasticizers, lubricants, as well as flame retardants in polymer materials. However, the flame retardant efficiency of ILs reported in literature isn’t high. Especially some even possess chlorine element.. In this project, different phosphorous-containing units including cage phosphate, spirobisphosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), etc., have been introduced into imidazolium cation via various N-alkylation or N-acylation reaction. Besides, by adjusting the species and length of anions, this phosphorus-containing ILs will have different polarity, which will improve their compatibility with polymer materials. The constitution and structure of ILs has great effect on their melting points, viscosity, density, polarity and thermal stability, etc., which will be investigated in detail. The obtained phosphorus-containing ILs with suitable physical properties will be chosen and used in polycarbonate (PC) and epoxy resin. The influence of amount and structure of phosphorus-containing ILs on the mechanical properties, flame retardancy, processing properties, thermal stability, as well as rheology behaviours of polymer matrix will be studied. The synergism effect of these flame retardant elements (P-N,P-N-S) and flame retardant mechanism will be clarified. This project will laid the theoretical basis for the usage of this new task-specific flame retardant ILs. Also, this project will provide a good idea for the molecular design of green, environmentally-friendly, high-efficient and multi-functional flame retardants.

在赋予高分子材料阻燃性能的同时，如何提高无机阻燃剂的阻燃效率，降低其添加量，保持材料的力学性能不受到损伤，是当前无卤环保阻燃领域亟需攻克的难题。本项目利用离子液体优异的分子设计性，将不同类型的含磷阻燃单体引入到咪唑阳离子上，同时调控阴离子的种类和长短，使这种新型离子液体不仅拥有磷、氮、硫等多种阻燃元素，同时还具有不同的极性以提高其与聚合物的相容性。通过这种方式所设计合成的离子液体不仅能够保持其自身不易挥发等绿色环保特点，还能赋予材料阻燃性，解决无机类阻燃剂与聚合物基材相容性差，导致材料力学性能严重下降的问题。详细研究离子液体的组成及结构对其熔点、热稳定、极性等物理性质的影响，找到其结构与性质的构效关系。详细研究含磷阻燃离子液体在聚碳酸酯以及环氧树脂中的应用情况，揭示离子液体的结构和用量对聚合物性能的影响，并提出其阻燃作用机理，为发展绿色、环保、高效、多功能的高分子新型阻燃剂提供科学依据。

在赋予高分子材料阻燃性能的同时，如何提高阻燃剂的阻燃效率，降低其添加量，保持材料的力学性能不受到损伤，是当前阻燃领域亟需攻克的难题。本项目利用离子液体优异的分子设计性，设计合成了8种不同类型的离子液体，既有磷修饰的咪唑阳离子型离子液体、也有季膦盐阳离子型离子液体；既有小分子离子液体也有聚离子液体；既合成了亲水型离子液体也合成了疏水型离子液体。详细研究了不同种类离子液体的熔点、热稳定性、黏度、溶解性等基本性质，并对其中两种离子液体的生物毒性进行了探究。将这些离子液体作为阻燃剂引入到聚碳酸酯、尼龙6、环氧树脂、聚乳酸、水性聚氨酯基材中，系统研究了离子液体对材料的阻燃性能、力学性能、热性能、固化行为等的影响，在某些聚合物体系中实现了添加少量离子液体即可赋予其阻燃性同时又维持/改善其力学性能的目的。此外，还运用多种研究手段对不同阻燃体系的阻燃机理进行了研究，提出了在不同体系中离子液体的阻燃作用机制。本项目揭示了离子液体/聚合物结构与性能的构效关系，阐明了多种离子液体的阻燃作用机制，为设计制备高效、绿色以及多功能的新型阻燃剂打下了坚实的基础，同时也为高分子材料阻燃高性能化提供了新思路。本项目已经完成既定的研究目标，在本项目的资助下，在Advanced Functional Materials、Chemical Engineering Journal、ACS Sustainable Chemistry& Engineering、Polymer等主流刊物上发表SCI收录论文14篇（均为第一/二标注），申请并获准中国发明专利2项，培养研究生5名。