【作者】 王宇；

【导师】 王武生； 曾俊；

【作者基本信息】 安徽大学 ， 高分子化学与物理， 2006， 硕士

【摘要】 水基聚氨酯以水取代传统溶剂作为分散介质，使用时具有不燃、气味小、无毒、无污染、节能、价廉、操作方便等优点，而且在性能上仍具有一般溶剂型聚氨酯所具有的高光泽、高耐磨性、高弹性、高粘结性、耐水、耐候、耐化学药品和对各种基材的良好附着性能，从而在很大的程度上取代了溶剂型聚氨酯，是一种极具潜力的“绿色材料”。水基聚氨酯代替溶剂型的聚氨酯将是聚氨酯工业发展的最终方向。 采用内乳化工艺合成的水基聚氨酯分散体，具有优异的稳定性和杰出的成膜性能，但内乳化工艺在聚氨酯分子结构中引入了亲水基团，分散体成膜后其亲水基团保留在膜材料中，使得水基聚氨酯膜材料在水的侵蚀下，可能出现溶胀而失去材料的机械性能；作为涂层材料使用时，耐湿擦性能不足，涂层长期在水的作用下发白、起泡、剥离。因此，提高水基聚氨酯材料的耐水性，一直是水基聚氨酯研究的核心。本课题在广泛总结文献已经报道的各种方法改性水基聚氨酯的基础上，创造性地提出以非极性链段来改性水基聚氨酯，提高材料的耐水性。具体改性工作分为两部分进行： 其一，饱和脂肪烃基改性水基聚氨酯分散体。在合成聚氨酯预聚体时，添加含有17个碳原子的长链脂肪烃的硬脂酸单甘油酯，在聚氨酯大分子侧链上引入强疏水性基团脂肪烃基。饱和脂肪烃基改性后的水基聚氨酯膜材料中，脂肪烃基在其表面形成了富集，将羧基和氨基甲酸酯基团排斥出膜材料表面，随着体系中非极性链段脂肪烃基含量的增加，聚氨酯膜材料的吸水率逐渐降低。制得的改性聚氨酯分散体具有较好的柔软性、相对优异的机械性能、杰出的耐水性。 其二，不饱和脂肪烃长链改性水基聚氨酯分散体。通过合成预聚体时添加聚丁二烯二醇，在聚氨酯大分子主链上引入含有碳碳双键的强疏水性非极性链段。研究更多还原

【Abstract】 Aqueous polyurethane dispersions have been used for a wide range of commercial applications, including adhesives, coatings for textiles, leather, rubber, and many polymeric substrates, because of their good strength and flexibility characteristics. Since they use of little or no organic solvent in aqueous polyurethane dispersions, they are nontoxic and nonflammable and do not pollute the air compared to their solvent-based counterparts.Aqueous polyurethane dispersion which is functionalized with hydrophilic side groups to render it self-dispersible in water offer outstanding stability and extraordinary film-forming properties. However, the disadvantage of this approach suffers from poor water resistance for introducing hydrophilic group in the bone of polyurethane molecular. It may be swelling for immersion in water and lost mechanical properties, and peeling off from substrates. In the sum of a great deal of literatures about various methods of modification of aqueous polyurethane, we provided a novel method to modify aqueous polyurethane by adding hydrophobic group to improve the ability of water-resistance. Our works include the following two parts:First, aqueous polyurethane was modified with Glycerol Monostearate during preparing prepolymer of polyurethane; aliphatic alkyl saturated containing seventeen carbons as power hydrophobic group is introduced in the side chain of polyurethane. Study shows the hydrophobic segments enrichment on the surface of the film ejects hydrophilic groups of carboxyl and urethane from surface, with the amount of increasing hydrophobic chains, the water absorption rate of the film is gradually reduced. That means modified polyurethane using our method has marvelous water resistance. Further research indicated the modified polyurethane have good pliability, relative outstanding mechanical properties.Secondly, we study on synthesis and characteristic of the aqueous polyurethane modified by unsaturated aliphatic alkyl. HTPB (hydroxyl-terminated polybutadiene) is introduced into the macromolecular of polyurethane. Studies indicate: 1. the particle sizes of the modified aqueous PU更多还原