六方氮化硼纳米片的制备、功能化及其在导热聚合物中的应用

发布时间：2018-03-11 04:17

本文选题：氮化硼纳米片　切入点：冻融剥离　出处：《山东大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着高分子工业的发展,聚合物材料已经应用到生产生活的各个方面。但是聚合物的导热性质一直是限制其应用的主要因素,导热聚合物也成为了聚合物研究的一个重要研究领域。由于大部分聚合物是热的不良导体,通常要通过在聚合物中加入导热性好的填料,才能实现聚合物的优良导热性。因此导热填料的选择对于导热聚合物至关重要。随着纳米材料的兴起,纳米填料也逐渐被应用于聚合物中,其中六方氮化硼纳米片(h-BNNSs)具有非常好的热稳定性、抗氧化性、抗腐蚀性、低的介电常数等性质,特别是其面内超高的导热性,若能充分利用,可以非常有效提高聚合物的热导率。本论文主要研究了h-BNNSs的制备,并对其进行功能化后添加到导热聚合物中,制备了导热硅橡胶。分析了剥离得到的h-BNNSs及其功能化后的结构与性质,并研究了利用h-BNNSs制备的硅橡胶的导热性质和介电性质。论文主要开展了以下几个方面的工作：1.开发了一种新的制备h-BNNSs的方法—冻融剥离法,利用水在4℃时密度最大,结冰后体积膨胀的性质,来克服六方氮化硼层间的范德华力,实现h-BNNSs的剥离制备。分析了冻融的时间、次数及超声作用对剥离效果的影响,根据在剥离中间阶段六方氮化硼表面会产生鼓包的现象,提出了冻融剥离的机理。研究了冻融法制备的h-BNNSs的形貌、结构和光学性质,通过紫外-可见吸收测试,证实了六方氮化硼的带隙会随着片层的减少而变大。此方法具有简单易操作、对环境友好、普适性等优点,可适用于多种二维材料的制备,用此方法对石墨、WS2、 MoS2进行剥离,均取得了非常理想的效果。2.利用剥离后的h-BNNSs表面及周围的羟基悬挂键的作用对h-BNNSs进行功能化。采用乙烯基三甲氧基硅烷对h-BNNSs进行功能化,以甲苯做溶剂,通过甲氧基水解,进而与h-BNNSs上的羟基发生脱水反应,二者通过共价键相连。通过EDS、FTIR、XRD等表征,可以确定乙烯基三甲氧基硅烷与h-BNNSs共价相连。通过这种功能化作用,可以使h-BNNSs与多种聚合物通过化学键连接。3.通过化学键连接将h-BNNSs添加到硅橡胶中,制备了一系列不同h-BNNSs添加量的硅橡胶,提高了其热导性,热稳定性,改善了其介电性质。在该体系中,乙烯基三甲氧基硅烷起到桥连作用,其甲氧基水解后与h-BNNSs的羟基反应,乙烯基又可以与硅氢键发生加成反应,参与到硅橡胶的交联网络中。这种添加h-BNNSs的方法保证了h-BNNSs在聚合物中均匀分散。因此有效提高了硅橡胶的热导率和热稳定性。在一定范围内降低了硅橡胶的介电常数,降低了硅橡胶的介电损耗,特别是降低了其低频下的介电损耗。这些性质充分保障了硅橡胶在电子器件和能源系统中的应用。
[Abstract]:With the development of polymer industry, polymer materials have been applied to all aspects of production and life. But the thermal properties of polymers has been a major factor limiting the application of the conductive polymer has become an important research field in polymer research. Because most of the polymer is a poor conductor of heat, usually by adding fillers with good heat conduction. In the polymer, excellent thermal conductivity can be achieved. So the polymer conductive filler for conductive polymer is very important. With the development of nano materials, nano filler has been applied to polymers, including six boron nitride nanosheets (h-BNNSs) has very good thermal stability, oxidation resistance, corrosion resistance. Dielectric properties of low thermal conductivity, especially its surface high, if we can make full use of, can be very effective to improve the thermal conductivity of polymers in the thesis. Study on the preparation of h-BNNSs, and the function of add to the conductive polymer, conductive silicone rubber was prepared. The analysis of the structure and properties of h-BNNSs and its function obtained after stripping, and studied using h-BNNSs preparation of silicon rubber thermal conductivity and dielectric properties. The paper mainly carried out the work of the following aspects: 1. to develop a new method for the preparation of h-BNNSs freeze-thaw stripping method, using water maximum density at 4 DEG C, the nature of volume expansion after freezing, to overcome the force of Fan Dehua six boron nitride layer, stripped of the preparation of h-BNNSs. The analysis of freezing and thawing effect of time, frequency and ultrasonic effect on the stripping effect, according to the middle of the six party in the stripping of boron nitride surface bulge phenomenon, mechanism of freeze-thaw stripping was proposed. The freeze-thaw morphology prepared by h-BNNSs, the structural and optical properties, through UV Vis absorption test confirmed that the band gap of six cubic boron nitride with reduced layer becomes larger. This method is simple and easy to operate, environmentally friendly, universality, etc., can be applied to a variety of two-dimensional materials were prepared on graphite, WS2 with this method, MoS2 stripping from the function of h-BNNSs.2. were obtained good effect by h-BNNSs surface and around after stripping the hydroxyl dangling bond effect. Using the function of h-BNNSs, vinyltrimethoxysilane, toluene as solvent, by methoxy hydrolysis, and dehydration reaction with the hydroxyl groups in h-BNNSs. The two are connected by covalent bond. By EDS, FTIR, XRD characterization can be determined, vinyltrimethoxysilane is connected with the h-BNNSs. The functional role of covalent, can make h-BNNSs with a variety of polymer through chemical bond to h- through chemical bond.3. BNNSs added to the silicon rubber, a series of different amount of h-BNNSs silicone rubber was prepared to improve its thermal conductivity, thermal stability, improve its dielectric properties. In this system, vinyltrimethoxysilane play a bridging role, the hydroxylation of methoxy after hydrolysis with h-BNNSs vinyl, and can react with silicon and hydrogen bonds involved in the crosslinking network of silicone rubber. This method of adding h-BNNSs to ensure that the h-BNNSs uniformly distributed in polymer. It can effectively improve the silicon rubber thermal conductivity and thermal stability. In a certain range reduces the dielectric constant of silicon rubber, reduce the dielectric loss of silicon rubber, especially reduce the dielectric loss of the low frequency. These properties fully guarantee the application of silicone rubber in the electronic devices and energy systems.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ128;TB383.1

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