Sythesis and Properties of Waterborne Polyurethane/silica/Silver Nanocomposites

• Main Authors: Shiao-Chieh Chen, 陳筱潔
• Other Authors: Chih-Chi Chen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/23313374493885351281

碩士 === 中原大學 === 化學工程研究所 === 99 === Firstly, waterborne polyurethane(WPU)/silica dispersions were prepared through a prepolymer mixing process. Then, different amounts of aqueous AgNO3 solutions were added to the WPU/silica dispersions to form WPU/silica/AgNO3 dispersions. There are three parts in this study as (1) preparation and properties of WPU/silica composites, (2) properties of WPU/silica/AgNO3(10wt%) composites with 0~8wt% silica, (3) morphology and properties of WPU/silica(2wt%)/AgNO3 composites with 2~10wt% AgNO3. Also in parts (2) and (3), AgNO3 in the composite films was partially reduced to Ag by heating the films at 120oC for a certain time period to form WPU/silica/Ag composite films. Subsequently, morphology and properties of the reduced composite films were compared with those of the original composite films. A particle sizer, a coaxial cylinder rheometer and a zeta potential analyzer were used to measure characteristics of the composite dispersions. A Fourier transform infrared spectrophotometer, a scanning electron microscope, a transmission electron microscopy, an electron spectroscopy for chemical analysis, an X-ray diffractometer, A atomic force microscopy and a contact angle analyzer were used to characterize structure and morphology of the composite films. Moreover, a thermogravimetric analyzer, a dynamic mechanical analyzer and a uniaxial stress-strain tester were used to measure thermal and mechanical properties of the composite films. Antibacterial property of the composite films was evaluated by the standard method.( CNS13907、CNS14945) Results of the three parts are list in the following: (1) Average particle size and stability of the WPU/silica emulsion increases and decreases, respectively, with increasing silica content. Moreover, hydrophilicity, thermostability and mechanical strength of the composite film increase with increasing silica content. (2) Tensile Ⅳ strength and elongation of the WPU/silica composites increased when AgNO3 was added, whereas the thermal decomposition temperature remained invariant. As partial AgNO3 was reduced to Ag by heating process, tensile strength and thermal decomposition temperature of the composites decreased, whereas elongation increased. (3) Tensile strength, elongation, thermal decomposition temperature, conductivity and antibacterial property of the WPU/silica/AgNO3 composites increased with increasing AgNO3 content. As partial AgNO3 was reduced to Ag by heating process, size of aggregated Ag particles on the surface and antibacterial property of the composites increased.