【作者】 袁晓芳；

【导师】 吕志平；

【作者基本信息】 太原理工大学 ， 化学工艺， 2003， 硕士

【摘要】 聚氨酯弹性体由于综合性能出众而被广泛应用，但由于其耐热、耐极性溶剂性能不好，所以其应用还是受到一定程度的限制。为了进一步拓宽其应用领域，本文考察研究了聚氨酯/沸石分子筛、聚氨酯/有机蒙脱土复合材料的力学性能、耐热性能及耐极性溶剂性能。 本文首次提出了“孔约束”的理论假说，即在高分子材料聚合过程中，线型分子的一端通过化学键或超分子作用力插入分子筛的孔道中形成硬端，而另一端则与其它单体分子缩合或聚合形成高分子材料的软端；在此假说的基础上，设计了一类孔约束型有机—无机复合高分子材料的新模式，即聚氨酯/沸石分子筛复合材料。 分子筛是一类硅酸盐材料，其对物质分子的吸附具有择形选择性，本文所选的是微孔分子筛。由于分子筛晶穴内部有强太原理工大学硕士学位论文摘要大的库仑场和极性作用，再加上骨架中大量平衡骨架负电荷的可交换阳离子的暴露造成的高电场梯度及表面的不均性，使其对水、极性分子及可极化的分子具有高选择的吸附性能。所以当把分子筛加入到低聚物多元醇中后，第一由于低聚物多元醇是略具极性的分子，第二由于直链分子的动力学半径(约o.49nm)小于所选分子筛的孔口尺寸，所以低聚物多元醇分子就会蠕动进入分子筛孔内，且一端吸附在孔内，固定于填料表面;另一端留在孔外，与孔外的甲苯二异氰酸醋反应，形成以分子筛为铰链的交联聚合物，分子筛的存在使聚合物交联的密度提高;另外，由于分子筛表面富含硅轻基，所以异氰酸酷的一端可与经基发生化学反应进而通过形成化学键接枝到分子筛上，另一端的反应活性则又使聚合物分子与分子筛牢固结合在一起而形成网状结构，从而提高了聚氨醋弹性体的力学性能、耐热性能及耐极性溶剂性能。 本文通过XRD、FTIR、TG等分析手段对复合材料的结晶形态、分子筛表面的反应性及其对聚合物的吸附组装进行了考察验证。XRD测试结果证实了有机蒙脱土在聚氨酷体系中能够剥离成纳米粒子，而聚氨醋/沸石分子筛复合材料中分子筛仍保持原来的晶型结构;FTIR谱图验证了异氰酸酷(TDI)可 太原理工大学硕士学位论文摘要与沸石分子筛表面的硅经基进行接枝反应形成稳定的化学键;而TG分析结果则进一步证实了分子筛的穿孔机理。 本文详细比较了沸石分子筛、有机蒙脱土等填料对聚氨醋的改性效果。力学性能、耐热性能、耐溶剂性能的测试结果均显示:无论在聚酷(PEG)、聚醚(PPG)还是聚四亚甲基醚二醇(PTMEG)体系中，当采用一步法工艺、氰轻比(NCO/OH)为1.1时，填料含量为5%的聚氨酷的综合改性效果最好，与纯PU相比，经分子筛改性的聚氨醋的扯断伸长率、耐撕裂强度、抗张强度、耐溶剂性最好可分别提高70%、80%、100%、40%以上;沸石分子筛和有机蒙脱土改性的聚氨酷的各项性能均优于普通无机填料粒子改性的聚氨酷;沸石分子筛改性的聚氨酷的力学性能和耐热性能基本与有机蒙脱土改性的聚氨酷相当，而耐溶剂性优于后者。 本文讨论了分子筛改性聚氨酷的特殊机理，不仅为聚氨酷改性提供了一种新的方法，同时也为改性聚合物提供了一个新的思路。更多还原

【Abstract】 Polyurethane(PU) elastomer has been widely applied because of its fine comprehensive properties. But its heat resistance properties and solvent resistance properties don’t very well, which limit its application in a certain. In order to widen the realm of application, mechanical properties, heat resistance properties and solvent resistance properties of PU/zeolite, PU/montmorillonite (PU/MMT) composite materials are discussed in this paper.The theory hypothesis of "pore restriction" is first proposed in this paper. During polymerization, one end of linear molecule inserts the channels of zeolite to form hard end through chemical bond or supermolecule acting force, the other end forms soft end through condensing or polymerizing with other monomer molecule. On the basis of the theory hypothesis, a kind of novel pattern of organic-inorganic composite materials-PU/zeolite composite materials-has been designed.Zeolite is a kind of silicate materials and it has shape selectivity. Microporous zeolites are chosen in this paper. It has high selectivity in adsorpting water , polar molecule or polarizable molecule on account of the existing of mighty coulomb field and polar interaction in the internal of crystal cave of zeolite, the high electric field gradient and the uneven surface caused by the exposure of exchangable cation of equilibrium framework negative charge in framework structures. By reasons of its mildly polarity and its kinetic radius which less than pore-opening size of the chosen zeolites, oligopolyols will wiggle into the channels of the zeolite when adding zeolite to oligopolyols. The existing of zeolite in PU made the crosslinking density improved. Thus mechanical properties, heat resistance properties and solvent resistance properties of PU are greatly enhanced.Crystal forms of composite materials, surfacial reactivity and adsorption assemble properties of zeolite are discussed in this paper by means of XRD, FTIR and TG etc. The test results of XRD prove that MMT can be exfoliated into nanocomposites in PU/MMT, while zeolite keep its original crystal structure in PU/zeolite. The spectras of FTIR prove that TDI can graft on the surface of the zeolite. Perforating mechanism is further illustrated by TGA.The modifying effects on PU of different fillers such as zeolite, MMT etc are discussed in this paper. The test results show that the properties of PU are almost all best when using "one step "processing, NCO/OH equaling 1.1, the content of fillers being 5%. Compare to pure PU, the elongation percentage at break, tear resistance, tensile strength, solvent resistance of PU modified with zeolite can be improved about 70%,80%,100%,40% respectively. All properties of PU/zeolite, PU/MMT are superior to PU modified with ordinaryfillers. Mechanical properties and heat resistance properties of PU/zeolite are correspond to those of PU/MMT, but the solvent resistance properties of the former are preferable.The special mechanism of PU which modified with zeolite is studied in this paper. There may be not only a new way to modifying PU, but also a new thought of modifying polymer.更多还原