導熱型相變化複合材料之研究

A study of conductive medium/phase change material composites

曾彥霖(Yen-Lin Tseng)

指導教授 ： 石燕鳳

朝陽科技大學/理工學院/應用化學系/碩士(2014年)

摘要

本研究以甲基丙烯酸甲酯及矽烷化合物之共聚物當外殼材料，並以石蠟(paraffin)當作核心材料，利用懸浮聚合法製備相變化微膠囊複合材料(microencapsulated phase change materials；MicroPCMs)，並於相變化微膠囊殼層材料中加入氮化鋁(AlN)與氧化鋁(Al2O3)，製備具有高導熱、高潛熱值之相變化微膠囊。並對此導熱型相變化微膠囊之特性進行探討，實驗結果顯示，相變化微膠囊粒徑大小在5μm左右，隨著穩定劑聚乙烯醇濃度增加，粒徑會有減小的趨勢。結果顯示由氧化鋁所製備出的微膠囊外殼導熱係數為0.7151 W/mK，石蠟含量為70.2%。由氮化鋁所製備出的微膠囊外殼熱傳導係數為1.0518 W/mk，石蠟含量為72.8%，由電池模組分析顯示散熱效果可提升22%以上。50次冷凍循環分析顯示此兩種微膠囊之熱穩定性良好，熱分析亦顯示此兩種微膠囊，耐熱性皆可達到200℃以上，因此兩者有極好的潛能作為熱儲存材料。

關鍵字

氧化鋁 ； 氮化鋁 ； 相變化微膠囊 ； 石蠟 ； 熱傳導係數

並列摘要

In this study, the microencapsulated phase change materials (MicroPCMs), were prepared by suspension polymerization. The shell was made of the methyl methacrylate-vinylsilane copolymer, and the core was paraffin. Moreover, aluminum nitride (AlN) and aluminum oxide (Al2O3) were incorporated to the shell to bring highly thermal conductive and large latent heat- MicroPCMs The result shows that the diameters of MicroPCMs were around 3.2-11.3 μm, and were decreased with the increasing concentration of stabilizer (Polyvinyl alcohol). As for the thermal conductivity of the shell, the aluminum oxide and aluminum nitride containing MicroPCMs are 0.7151 and 1.0518 W/m‧k, respectively. The paraffin contents are 70.2% and 72.8%, respectively. After thermal cycling of 50 times, both MicroPCMs still keep excellent stability. TGA results show that the decomposition temperatures of both MicroPCMs were higher than 200℃. The test on a battery module shows that aluminum nitride containing MicroPCM can improve the heat dissipation by more than 22%. On the basis of these results, such MicroPCMs show good potentials for thermal energy storage.

並列關鍵字

aluminum oxide ； aluminum nitride ； microencapsulated phase change materials ； paraffin ； thermal conductivity

參考文獻

4. Y. Ma, X. Chu, W. Li, “Preparation and characterization of poly(methyl- methacrylate-co-divinylbenzene) microcapsules containing phase change temperature adjustable binary core materials,” Solar Energy, 7(86), 2056-2066 (2012).

5. E. Gunther, S. Hiebler, “Enthalpy of Phase Change Materials as a Function of Temperature: Required Accuracy and Suitable Measurement Methods,” International Journal of Thermophysics, 4(30), 1257-1269 (2009).

6. B. S. Pramod, S. S. Prashant, “A review on effect of phase change material encapsulation on the thermal performance of a system,” Renewable and Sustainable Energy Review, 8(16), 5603-5616 (2012).

7. C. Alkan, “Enthalpy of melting and solidification of sulfonated paraffins as phase change materials for thermal energy storage, ” Thermochimica Acta 1(451),126-130 (2006).

8. B. Zalba et al., “Review on thermal energy storage with phase change: materials, heat transfer analysis and application,” Applied Thermal Engineering, 3(23), 251-283 (2003).