| Summary: | 碩士 === 弘光科技大學 === 職業安全與防災研究所 === 97 === In the study, preparation and properties of green flame retardant of silane functionalized expandable graphite composites were investigated. The coupling agent was used to improve the interface between the matrix and expandable graphite. Furthermore, the obtained expandable graphite was put into the high-temperature oven at 1000℃ for 15s. The expanded graphite was dispersed in a alcohol solution and then subjected to power in ultrasonic bath for 8hr. The obtained mixture was filtered and then dried to get nano-level graphite sheets then prepared nano-composites.
FT-IR, XPS and 29Si-NMR were adopted to characterize the functionalized expandable graphite. FT-IR showed that absorption peaks at around 1100-1000cm-1, corresponding to –OEt functional group. In addition, the silica network was characterized by 29Si-NMR. Results revealed that T3 are the SiO2 network structures. XPS presented that APTS molecules reacted with the carboxyl acid functional group of expandable graphite. It was affirmed that APTS has been grafted on expandable graphite.
Thermal properties showed significant difference between the conventional composites and nanocomposite. The modified expandable graphite composites exhibited promising thermal properties. TGA and TG△ were employed to calculate the thermal sTableility. The modified expandable graphite composites improved thermal property, corresponding to functionalized expandable graphite. The 10% weight loss temperature increased from 278℃ to 340℃. The L.O.I of the composites can reach 28. Hence, the materials possess excellent flame-retardant properties.
SEM was used to study the morphology property of the modified expandable graphite composites. It showed that flake graphite existed in the matrix. EDX indicated that Si atoms appeared due to APTS was grafted on expandable graphite. The expanded structures of graphite were formed after burned. The foamed layer demonstrated to the mechanism of protection of expandable graphite. Furthermore, XPS was used to prove that the graphite can improve the anti-oxidant ability of material.
Functionalized nano-sheet graphite contributes to improve the heat-conduction and reduce the surface resistance of composites. TEM, XRD and SEM were used to study the structure of composites. The antistatic properties of GNs composites can reach the conductive level.
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