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標題: Preparation and physical properties of silicone oil/silica fluid nanocomposites
作者: 蔡秉凱
關鍵字: silicone oil;silica;fluid;nanocomposites
出版社: 化學工程學系
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)

摘 要
本研究利用八甲基環四矽氧烷與六甲基二矽氧烷以硫酸當觸媒而合成矽油,發現當硫酸添加量1.0 wt %,約反應5~6小時可達所需之黏度。由29Si-NMR分析其結構,矽油之(-Me2SiO-)的特徵吸收峰(D2)出現在約-22 ppm,封端基(Me3SiO-)的特徵吸收峰(M)則出現在約6 ppm,且其表面張力為20 ~ 21 mN / m。同時使用環氧基矽氧烷偶合劑與D4來改質二氧化矽,由FTIR分析,發現1254 cm-1為epoxy ring breathing吸收峰,822 cm-1為非對稱ring stretching吸收峰,1028 cm-1為矽油Si-CH3 rocking吸收峰,1263 cm-1為矽油甲基之CH deformation吸收峰。固態29Si-NMR分析其結構,-68.52、-57.03及-48.71 ppm為二氧化矽與環氧基矽氧烷偶合劑之鍵結所生成之波峰。純水與未改質二氧化矽之接觸角為19.0 o,與改質之二氧化矽之接觸角為91.0 o。添加1、3 phr改質之二氧化矽於矽油中以製備流體複材,其黏度由976.8 cp分別提升至1184 cp及1431 cp,50 wt %熱裂解溫度則由544 ℃分別提高至572 ℃與578 ℃(針對市售矽油mO970)。以UV測定不同濃度之吸收值,得知改質之二氧化矽在矽油中分散相當均勻。以FE-SEM分析矽油中二氧化矽之分散性,顯示改質之二氧化矽其粒子大小分布在25 ~ 50 nm。由DMA分析,添加1、3 phr改質二氧化矽於矽油中之tanδ由5.35分別上升至8.02與13.36(針對市售矽油mO970)。
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