【作者】 邓惠勇；

【导师】 官建国；

【作者基本信息】 武汉理工大学 ， 材料学， 2003， 硕士

【摘要】 本文是在查阅了大量国内外文献的基础上，依据雷达波吸收材料研究的基本理论和设计方法，以羰基铁为重点研究对象，采用原位复合的方法制备环氧树脂（EP）包裹羰基铁、超微铁包裹中空玻珠以及中空玻珠／超微铁／EP三层结构复合粒子。用SEM、TEM、XRD、FTIR、Zeta电位表征复合粒子的结构；用DTA-TG分析复合粒子的热稳定性；用矢量网络分析仪研究材料的复介电常数（ε=ε′-jε″）和复磁导率（μ=μ′-jμ″）。探讨了微观结构对材料性能的影响。 用ATPU／Span60作表面活性剂，在DMF溶剂中，热分解五羰基铁后，加入环氧树脂（E-44）减压蒸馏，制备了EP包裹超微铁复合粒子。研究结果表明：复合粒子结构为EP包裹超微铁（α-Fe）核壳结构，该结构提高了复合粒子的抗氧化能力。用ATPU作表面活性剂制备核壳结构复合粒子时，随着复合时ATPU用量的增加，复合粒子的密度、复介电常数（ε）和复磁导率（μ）逐渐减小，剩磁与矫顽力逐渐增大。ε′、μ′和μ″均随频率的增大而减小；ε″随频率的变化与ATPU的用量有关，当ATPU用量＜2.32％时，ε″随频率增大而减小，但当ATPU用量＞2.32％时，ε″随频率的变化不明显。五羰基铁浓度对复合粒子的静磁性能影响不明显。用ATPU和Span60作表面活性剂制备核壳复合粒子时，随着复合时Span60用量的增加，复合粒子的密度、ε减小，μ先减小后增大。随着频率的增大，复合粒子ε、μ呈减小趋势。随着复合时ATPU用量的增加，复合粒子的密度减小，ε、μ先减小后增大。指出了复合粒子密度的变化是由于有机相含量与超微铁粒径的变化引起的，并用界面缺陷的理论探讨了微观结构对ε与μ的影响。 用ATPU作表面活性剂，在中空玻珠存在下“原位”热分解五羰基铁制备出中空玻珠／超微铁核壳复合粒子。研究表明：ATPU的醚键（-CH₂CH₂-O-CH₂CH₂-）与中空玻珠表面的（-OH）形成了氢键；氨基与Fe之间以配位键作用。随着中空玻珠用量的增大，复合粒子包裹率逐渐降低。分析ATPU对复合粒子包裹致密性的影响可以得出，当ATPU用量很少时，不仅复合粒子包裹得不致密，而且微粒Fe团聚现象比较明显，当ATPU用量继续增大后，微粒铁的粒径变化不明显，但复合粒子的致密性有所下降。随着中空玻珠用量增大，声“减小，夕‘先增大后减小。随着ATPU用量增大，尸减小，￡先减小后增大，但当ATPU的浓度>6 .7mg/ml，￡“随ATPU用量的改变不明显。指出了由于采用中空结构，复合粒子的密度减小，并且能够较大范围调节复合粒子的￡、夕。 通过在超微铁包裹中空玻珠复合粒子表面再包裹一层EP，制备出了中空玻珠/超微铁/EP三层结构复合粒子。结果表明:此复合粒子较中空玻珠/超微铁复合粒子有更好的致密性。随着ATPU用量的增大，超微铁粒子粒径变小，包裹层变得更加均匀，￡减小，夕先减小后增大。但当f>16GHz，:变化剧烈。更多还原

【Abstract】 Having consulted all the available literature on the subject, according the basic principal and method of design of radar absorbing materials, composites of epoxy resin (EP)-coated ultramicro iron, ultramicro iron-coated hollow glass bead, and hollow glass bead /ultramicro iron/ EP with three-layer structure were prepared. Microstructure of composites was characterized through SEM, TEM, XRD, FTIR, and Zeta potential; Thermal stability was investigated through DTA-TG; Complex permittivity and complex permeability were investigated by vector net analysis. Influence of microstructure of composites on electromagnetic properties was discussed.Composites of EP coating ultramicro iron were prepared using ATPU&Span60 as surface agent in DMF solvent by decomposing carbonyl iron and then vacuum distillation after adding epoxy resin (E-44). The results showed: Composites showed microstructure of EP coating ultramicro iron( α -Fe), which could enhance the ability of antioxidation of composites. Having investigated composites of EP coating ultramicro iron using ATPU as surface agent, results showed that with increasing amount of ATPU, density , complex permittivity ( ε ) and complex permeability (μ ) of composites decreased, and retentivity and coercivity increased. ε’μ’ and μ" decreased with increasing frequency. Change of ε " with frequency was concerned with the amount of ATPU. When the amount of ATPU was less than 2.32%, ε " decreased with increasing frequency, but when the amount of ATPU was greater than 2.32%, influence of frequency on ε " was not obvious. Influence of concentration of carbonyl iron on static magnetism was not obvious. During discussing composites of EP-coated ultramicro iron through surface agent ATPU & Span60, we could find that with increasing the amount of Span60, density, ε decreased; μ decreased firstly and then increased; With increasing frequency, ε and μ decreased. In addition, with increasing the mount of ATPU, density of composites decreased, ε and μ decreased firstly and then increased. Density of composites was varied with the amount of organic and grain size of ultramicro iron. Influence of microstructure on ε and μ was discussed with the interface defectmechanism.Composites of ultramicro iron-coated hollow glass bead were in-suit prepared using ATPU as surface agent by decomposing carbonyl iron in hollow glass beads and DMF mixed solution. The results showed: The interaction of ether linkage (-CH2CH2-0-CH2CH2-)of ATPU and hydroxy group(-OH) of the surface of hollow glass bead formed hydrogen bond; Amino group and iron formed coordination bond. With increasing the amount of hollow glass beads, the ratio of ultramicro iron-coated hollow glass bead decreased. Having analyzed the influence of ATPU on compactness of composites, we could conclude that when the amount of ATPU was less, not only compactness of composites was poor, but also congregation of ultramicro iron was obvious. With increasing the amount of ATPU further more, change of grain size of ultramicro iron was not obvious, but compactness of composites decreased. With increasing the amount of hollow glass bead, ε and μ " decreased, μ ’ increased firstly and then decreased. With increasing the amount of ATPU, V decreased, and ?decreased firstly and then increased; But when the concentration of ATPU was greater than 6.7mg/ml, change of ε " with increasing of concentration of ATPU was not obvious. It was pointed that density of composites decreased and ε and μ could be adjusted due to hollow structure.Composites of hollow glass bead /ultramicro iron/ EP with three-layer structure were prepared by coating EP on the surface of composites of ultramicro iron-coated hollow glass bead. The results showed: Composites had better compactness than composites of ultramicro iron-coated hollow glass bead. With increasing the amount of ATPU, grain size of ultramicro iron decreased, compactness of composites enhanced, ε decreased, and μ decreased firstly and then increased. But when frequency was greater更多还原