聚氨酯/复合金属颜料涂层的制备及红外发射率

Preparation and Infrared Emissivity of Polyurethane/Composite Metal Pigments Coatings

以铝(Al)粉及青铜(Bronze)粉为复合颜料,聚氨酯(PU)为粘合剂,制备PU/AlBronze复合涂层,研究了涂层的微结构和红外发射率。结果表明:PU/AlBronze复合涂层具有类似一维光子结构特征,其发射率可低至0.186,且明显低于以单一金属颜料所制备的FU/Al及PU/Bronze涂层的发射率。其原因,一是复合涂层中由一维光子结构引起的反射光谱具有明显的多重反射峰;二是相比以高密度金属颜料制备的PU/Bronze涂层,PU/AlBronze涂层的表层树脂层的厚度明显降低,从而使其对涂层发射率的增量明显降低。

Polyurethane （PU）/AIBronze composite coatings were prepared by using flaky AI and bronze powders and PU as composite pigments and adhesives, respectively. The microstructure and in- frared emissivity of the coatings were systematically investigated by scanning electron microscopy, infra- red emissometer and theoretical simulation. The results show that PU/AIBronze composite coatings have similar one-dimensional photonic structural characteristics. The infrared emissivity of PU/AIBronze com- posite coatings with composite metal pigments is as low as 0.186 at the pigments content of 40%, and it is significantly lower than that of PU/AI and PU/Bronze composite coatings with single metal pigments. The reasons for this phenomenon are： （1） the reflection spectra of one-dimensional photonic structure in PU/AIBronze composite coatings have multiple reflection peaks; （2） comparing to PU/Bronze composite coatings with high density metal pigments, PU/AIBronze composite coatings have lower thickness of sur- face resin layer, reducing the emissivity increment of the coatings significantly.