水性聚氨酯/四氧化三铁纳米复合材料的制备与性能

Preparation and properties of waterborne polyurethane/ferroferric oxide nanocomposites

以KH550(γ-氨丙基三乙氧基硅烷)为氨基化试剂,通过硅烷反应使其键合于Fe_3O_4纳米颗粒表面,得到了表面氨基化的磁性纳米Fe_3O_4纳米颗粒.以异氟尔酮二异氰酸酯和磺酸盐水溶性聚酯二元醇为原料,2,4-二氨基苯磺酸钠为扩链剂,通过预聚体法制备水性聚氨酯;并在制备聚氨酯预聚体的过程中,引入氨基化改性的Fe_3O_4纳米颗粒,在纳米颗粒和聚氨酯之间建立化学键接,基于原位聚合法合成了系列水性聚氨酯/四氧化三铁复合材料.采用FTIR、SEM、XRD等测试手段对Fe_3O_4纳米颗粒和复合材料的结构特性进行了表征.研究了不同添加量的Fe_3O_4对水性聚氨酯/四氧化三铁复合材料力学性能和磁性的影响.研究表明,当Fe_3O_4含量小于3%时,纳米粒子可在复合材料均相分散,复合材料呈现较高的力学性能和热性能.复合材料的磁性亦随着Fe_3O_4的增加而增大,磁饱和值可以达到22.8emu/g,且在室温下具有超顺磁性.

Fe3O4 nanoparticles surface functionalized with amino groups were prepared through silanization reaction withγ-aminopropyl triethoxysilane（KH550）as amination reagent.And waterborne polyurethane was synthesized by prepolymer method with isophorone diisocyanate（IPDI）and sulfonated polyester glycol as raw materials,and sodium 2,4-diaminophenylsulfonate as chain extender.In the preparation process of polyurethane prepolymer,amino-functionalized Fe3O4 particles were introduced and chemical bonds were built between Fe3O4 particles and polyurethane chains,and a series of waterborne polyurethane/Fe3O4 composite was thereby obtained based on in situ polymerization.The structural characteristics of Fe3O4 particles and composites were characterized by IR,SEM and XRD.Effects of Fe3O4 content on the mechanical and magnetic property of composites were investigated.It was found that the nanoparticles dispersed in the composites in a uniform style,and the composites were endowed with higher mechanical and thermal property when the Fe3O4 content was lower than 3%.The magnetic strength of composites increased with increasing Fe3O4 content,and the magnetic value at saturation reached 22.8emu/g,the composites displayed superparamagnetism at room temperature.