Preparation and physical properties of silicone oil/silica fluid nanocomposites

• Main Author: 蔡秉凱
• Other Authors: 吳震裕
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/77900561065482888693

碩士 === 國立中興大學 === 化學工程學系 === 92 === Abstract In this study, the silicone oil is synthesized via octamethylcyclotetrasiloxane（D4） and hexamethyldisiloxane by acid cayalyst and under the dosage of sulfuric acid is 1.0 wt ％, the viscosity reaches equilibrium after 5 ~ 6 hours. By 29Si-Nuclear Magnetic Resonane analysis, the absorbances of silicone in (-Me2SiO-) and (Me3SiO-) are close to -22 ppm and 6 ppm. Epoxy silane coupling agent（GPS） and D4 are used for the surface modification of silica. By Fourier Transform Infrared Spectrophotometer analysis, the absorbances of epoxy ring breathing is 1254 cm-1, asymmetric ring stretching absorbance is 822 cm-1, Si-CH3 rocking and CH deformation absorbances of silicone oil are 1028 cm-1 and 1263 cm-1. By Solid State 29Si-Nuclear Magnetic Resonane analysis, the bond absorbances of GPS and silica are at -68.52, -57.03 and -48.71 ppm. The contact angle of water on unmodified silica is 19.0 o and the contact angles of water on modified silica is 91.0 o. With the addition of 1 phr and 3 phr silica into silicone oil , the viscosity increase from 976.8 cp to 1184 cp and 1431 cp. The 50 wt ％ loss temperatures increase from 544 ℃ to 572 ℃ and 578 ℃ for commercial silicone oil, mO970. The particles size of modified silica are between 25 ~ 50 nm in silicone oil by FE-SEM analysis. By DMA analysis, the tanδof the silicone/silica composite fluid which containing 1 phr and 3 phr silica raise from 5.35 for pure oil to 8.02 and 13.36.（based on marketed silicone oil, mO970）