Preparation of Boron Nitride Nanosheets by Chemical Intercalation Exfoliation Method Applied on the Development of Thermal Conductive Silicone Pad

• Main Authors: Po-Yen Chhen, 陳柏諺
• Other Authors: Chung-Feng Jeffrey Kuo
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/64xpcv

碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 106 === In this study, the layers of hexagonal boron nitride (h-BN) were stripped by chemical intercalation and free radical polymerization to prepare boron nitride nanosheets (BNNSs) to solve the current preparation of boron nitride nanosheets. The size of the nano tablets cannot be controlled, the process is complicated, and the like, and the achieve size control and the process are simple. The h-BN, BNNSs and spherical alumina (Al2O3) were applied to the filling of the silicone rubber to prepare the Thermal Conductive Pad. The difference between the thermal conductivity and the mechanical properties of the single and composite particles was discussed. The optimal parameters design of BNNSs preparation, thermal conductivity silicone pad preparation and thermal conductivity silicone pad experiment are discussed in three parts. The method of composite particles and filled nanofiller is used to solve the problem of limited thermal conductivity of single filler. In the state, the thermal conductive rubber pad can have the purpose of high thermal conductivity and high mechanical properties. The first part is the preparation of boron nitride nanosheets. The raw material composition is h-BN, and the intercalation agent dimethyl acrylamide (DMAA) provides ammonium salt ions for intercalation. The Azobisisobutyronitrile (AIBN) initiates a radical polymerization reaction with the intercalation agent in a thermal environment to promote molecular growth and achieve the effect of exfoliation. XRD and FE-TEM were used to analyze the interlayer distance and crystal structure of BNNSs. FE-SEM analysis of BNNSs sheet thickness, the results show that adding AIBN 0.1 phr, reaction time of 24 hours, interlayer distance of up to 0.35 nm, sheet thickness of 5 nm, and BNNSs chemical intercalation After the peeling, its crystal structure was not destroyed. The second part is the preparation of a thermal conductive rubber pad. The first part of BNNSs was filled into ruthenium rubber to prove the high thermal conductivity of BNNSs. The experimental results confirmed that single-filled BNNSs can improve the thermal conductivity and mechanical properties of silicone rubber more than h-BN. Therefore, Al2O3 was added in this study. The method of composite particles is used to prepare a thermal conductive silicone pad of composite particles, which solves the problem of improving the thermal conductivity of a single filler. The results show that 60% by weight of Al2O3 and 20% by weight of BNNSs, thermal conductivity and tensile strength of 5.23 W/mK and 102 Psi, respectively, confirm that the thermal conductive mat prepared in this study is It can combine high thermal conductivity and high mechanical properties under the condition of reducing the powder filling amount. The third part is the optimization parameter design and experimental analysis of the thermal conductive silicone pad process. The Taguchi method and the Elimination et selection translating reality (ELECTRE) are used for experimental planning, and the number of complicated experiments and the cost is reduced to the minimum. The influence of each control factor on the quality characteristics of the thermal pad is discussed. The combination of the optimized process parameters is found, and the physical properties of the thermal pad are measured. The thermal conductivity and tensile properties of the thermal pad are measured. 5.14 W/mK and 102 Psi. It is confirmed that the filling of BNNSs can effectively improve the thermal conductivity and mechanical properties, and meet the demand specification for the use of commercially available thermal conductive silicone pads.