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在合成聚氨酯的反应初期(方式Ⅰ)和预聚反应过程中(方式Ⅱ)加入环糊精超分子准多轮烷(PR),制备出一系列环糊精准多轮烷改性聚氨酯复合材料(PU/PRs).环糊精准多轮烷使聚氨酯(PU)材料的拉伸强度、断裂伸长率和杨氏模量同步提高.其中,采用方式Ⅰ并控制多轮烷质量分数为0.73%,拉伸强度和断裂伸长率达到最大值,分别是纯聚氨酯的1.8和1.7倍.力学性能的提高主要归因于环糊精超分子准多轮烷的均匀分散并与基质形成的拓扑交联网络结构,即β-环糊精(β-CD)贯穿聚丙二醇(PPG)链段的多轮烷通过PPG的端羟基和环糊精分子的羟基与异氰酸酯基的反应融入聚氨酯基质的网络结构.但是,过高的准多轮烷含量不利于聚氨酯材料力学性能的提高.
A series of cyclodextrin quasi-multi-turn modified polyurethane composites were prepared by adding cyclodextrin supramolecular quasi-multi-rotaxane (PR) during the initial stage of reaction (mode I) and prepolymerization (mode II) PU / PRs). The cyclodextrin quasi-multi-rotaxane improved the tensile strength, elongation at break and Young’s modulus of polyurethane (PU) Tensile strength and elongation at break reached the maximum, respectively 1.8 and 1.7 times that of pure polyurethane.The improvement of mechanical properties was mainly attributed to the uniform dispersion of the cyclodextrin supramolecular quasi-multi-rotaxane and the topological cross-linking with the matrix The network structure, ie, β-cyclodextrin (β-CD), is a polyrotaxane that penetrates the polypropylene glycol (PPG) segment into the network structure of the polyurethane matrix through the reaction of the terminal hydroxyl groups of the PPG and the hydroxyl and isocyanate groups of the cyclodextrin molecule. However, too much quasi-multi-rotaxane content is not conducive to the improvement of the mechanical properties of polyurethane materials.