In this work, epoxy resin (EP)-based aqueous polyurethane (PU) anionic PU dispersion was synthesized by the prepolymer and self-emulsification method. The PU prepolymer was first synthesized to serve as seeds. Then, trimethylolpropane and A-type EP (E-51) were introduced into it, followed by neutralization and emulsification reactions, and, finally, it formed a crosslinking network structural waterborne PU emulsion. The effect of epoxy contents on the particle size, rheological properties, storage stability, thermal stability, mechanical properties, and hydrophilicity of the resulting PU films was systematically investigated. The results showed that the PU dispersions displayed excellent storage stability and crosslinking density, and the glass transition temperature of the composite films was increased. The properties of self-made epoxy-modified polyurethane emulsion and polyester-cotton fabric before and after finishing were tested. The wrinkle resistance, hydrophobicity, and strength of the finished polyester/cotton fabric are improved, and it exhibits better color fastness to washing and rubbing.

水性聚氨酯(WPU)是一种优异的绿色环保型高分子材料,广泛用于纺织材料、合成工业、建筑建造、生物医疗等领域,如纺织品涂层整理剂、水性木器涂料、皮革涂饰剂、固色剂、胶黏剂、沥青等,受广泛重视.目前WPU改性已成为多领域研究热点,是毒性溶剂型聚氨酯材料有前途的替代品之一.文章综述环氧树脂(EP)对WPU单组分改性和辅以其他适应性基材复合改性研究进展,并展望未来水性聚氨酯发展趋势.

In recent years, conductive polymer composites have been widely studied for their electrical conductivity and electromagnetic shielding effects due to their advantages of light weight, simple preparation methods, and structural design versatility. In this study, oxidized multi-walled carbon nanotubes/waterborne polyurethane composites (OCNT/WPU) were prepared by grafting oxidized carbon nanotubes onto polyurethane molecular chains through in situ polymerization, using environmentally friendly waterborne polyurethane as the polymer matrix. Then, the OCNT/WPU structure was broken by high shear force, and the loading of CNTs was increased by adsorption, and a new composite structure was designed (denoted by OCWPU). The structure and morphology of OCNT/WPU and OCWPU were characterized by FT-IR and SEM. The structure and morphology of OCWPU with different multi-walled carbon nanotube loadings (CNTs/OCWPU) were characterized by SEM, Raman. Finally, the electrical conductivity and the electromagnetic shielding properties of the composites were investigated. It was found that after application of high shear force, the structure of OCWPU was disrupted and the surface activity of the material increased. With the increase in CNTs content, CNTs formed a rosette structure in the polyurethane matrix and covered the surface, and its electromagnetic shielding effect in X-bond (8.2–12.4 Ghz) would be able to reach 23 dB at 5% CNTs/OCWPU and 66.5 dB at 50% CNTs/OCWPU to meet the commercial needs. With 50% CNTs/OCWPU, an electrical conductivity of 5.1 S/cm could be achieved. This work provides a novel idea for the structural design of conductive polymer composites, which can achieve greater performance with the same carbon nanotube content.

采用混合酸对多壁碳纳米管(MWCNTs)进行处理,得到具有反应性基团的功能化多壁碳纳米管(O-MW-CNTs);以聚乙二醇(PEG1000)和异佛尔酮二异氰酸酯(IPDI)为主要原料反应生成聚氨酯(PU)预聚体,然后通过原位复合法制备了PU/MWCNTs、PU/O-MWCNTs复合乳液;通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)及红外光谱仪(FTIR)等仪器表征分析了MWCNTs和O-MWCNTs的微观结构、表面形貌和分散性能,并通过FTIR对PU、MWCNTs/PU、PU/O-MWCNTs进行了结构特征分析.结果表明,混合酸处理使MWCNTs侧壁引入了约自身质量10.2％的含氧官能团,极大地提高了MWCNTs在PU基体中的分散性;O-MW-CNTs在PU预聚体形成之后加入时,会与PU链嵌段或者接枝,更利于分散;PU/O-MWCNTs复合乳液外观细腻呈黑灰色,静置36 h后O-MWCNTs仍呈现良好的分散性.