Modification of PVA by sol-gel process and evaluation of properties

• Main Authors: Jr-Yuan Jiang, 姜智遠
• Other Authors: Jen-Ming Yang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/44100932064937076326

碩士 === 長庚大學 === 化工與材料工程研究所 === 95 === In this study, we prepared organic-inorganic composite material of polymer electrolyte membrane via modification of poly(vinyl alcohol) (PVA) by sol - gel and discuss its electrical properties in cell system. First, we chosen PVA as the major base and then grafted the monomer of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AAc) by ultraviolet radiation. After that, we obtained two different components of PVA/poly(HEMA) and PVA/poly(acrylic acid) polymer. Then we used them as the basic material which was further modified by sol - gel. And we investigated their electrical property, thermal property, swelling test and structural analysis. According to the structural analysis, we could find that the crystallinity of PVA/poly(HEMA)/SiO2 and PVA/poly(Acrylic acid)/SiO2 became worse and the amorphous phase increased with silica content. By the thermal analysis, the Tm of the modified PVA moved to lower temperature with the increasing of silica content. But the degradation temperature moved to higher temperature, it proved that the material had better thermal stability. For the swelling test, the swelling of the membrane increased with the increasing time and reached equilibrium. In addition to increasing immersed rate, the swelling also increased with silica content. From the electrical properties test, we found the ionic conductivity of membrane increased with the increasing of SiO2 content and the increased temperature, and the range of clectrochemical stability were both about 1.5 V.