A study on water absorption in freestanding polyurethane films filled with nano-TiO_2 pigments by capacitance measurements  

作　　者：Mingcheng SUN Fuchun LIU Hongwei SHI Enhou HAN 

机构地区：[1]State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

出　　处：《Acta Metallurgica Sinica(English Letters)》2009年第1期27-34,共8页金属学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.50499334)

摘　　要：The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L NaCl solutions. EIS results were compared with gravimetric measurements on the freestanding films. The amount of water absorption showed great discrepancy between the two methods. The diffusion coefficient in the polyurethane film with P/B：30% was the smallest among those filled with nano-TiO2 pigments. The dielectric constant ε of the polyurethane varnish film obtained from the initial capacitance was in the range of typical values of polymers. SEM was used to measure the distribution of nano-TiO2 particles in the polyurethane films.The electrochemical impedance spectroscopy （EIS） was used to evaluate the water transport and dielectric properties of polyurethane films filled with nano-TiO2 at different pigment/base （P/B） values in 0.5 mol/L NaCl solutions. EIS results were compared with gravimetric measurements on the freestanding films. The amount of water absorption showed great discrepancy between the two methods. The diffusion coefficient in the polyurethane film with P/B：30% was the smallest among those filled with nano-TiO2 pigments. The dielectric constant ε of the polyurethane varnish film obtained from the initial capacitance was in the range of typical values of polymers. SEM was used to measure the distribution of nano-TiO2 particles in the polyurethane films.

关 键 词：Water absorption NANO-TIO2 POLYURETHANE EIS 

分 类 号：TG14[一般工业技术—材料科学与工程] TB383[金属学及工艺—金属材料]