氧化石墨烯类材料增强聚合物基纳米复合材料的制备与研究

发布时间：2018-01-08 16:07

本文关键词：氧化石墨烯类材料增强聚合物基纳米复合材料的制备与研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着便携式和可穿戴电子设备向小型轻薄多功能化方向的迅速发展进一步促进了集成电路的高功率密度化,为保证电子元器件长时间可靠运行,对电路热量的有效管理成为关键。石墨烯材料具有优异的热、力学等性能,被广泛用于提高电子封装用聚合物复合材料的热性能,但复合材料的热性能仍然与人们基于石墨烯材料优异性能所产生的预期相距较远,因此复合材料的热性能仍具有很大的提升空间。本论文以氧化石墨烯类材料(Graphene oxide,GO)为导热填料,以环氧树脂为基体,研究了 GO类材料对聚合物基体固化反应的影响,提出了进一步提高GO/聚合物基复合材料导热性能的方法,分析了GO类材料在提高聚合物基体导热性能的同时又增强热稳定性能的机理。主要研究内容及结论如下:(1)采用原位固化法制备了系列(0.5,1,2,2.2,2.5,3wt%)多层氧化石墨烯(Multi-layer graphene oxide,MGO)/环氧树脂复合材料,结果表明2wt%MGO复合材料的热导率最大,为纯环氧树脂的2.03倍。基于实时活化能研究发现了 2wt%MGO导热链使固化后期能垒急剧增加,但同时环氧树脂复合材料的固化程度也在增加,然而这种固化程度的差异在经过老化或热退火之后会消失,这表明大量来自2wt%MGO导热链的-OH,为孤立的/被困的剩余环氧分子突破能垒进行环氧分子-MGO反应提供了关键驱动力。针对MGO特殊的层状结构,提出了一种改进的缩核模型用于解释在环氧分子-MGO插层反应过程中阻力的变化。研究结果表明,通过促进插层交联反应的发生有利于进一步提高复合材料的热导率,但是反应阻力逐渐变大。根据动力学研究,提出了一种针对固化反应过程的优化方法用于促进插层交联反应,研究结果表明仅通过将后处理温度提高30℃就能够进一步提高复合材料的热导率,为纯环氧树脂的2.96倍。(2)采用原位固化法制备了系列氧化石墨烯纳米片(Graphene oxide nanoplatelet,GONP)/环氧树脂复合材料,研究了两种GONP(r-GONP和f-GONP,片径相近)的形貌特征、表面官能团含量、在基体中的分散/剥离状态、界面结合强度等对环氧树脂复合材料的导热性能、Tg以及尺寸/结构热稳定性的影响。研究结果表明:r-GONP(厚34nm)表面较平滑,呈相对刚性片状,而f-GONP(厚7nm)表面折皱起伏,呈柔性薄纱状;在不同含量下r-/f-GONPs在基体中都能够被进一步剥离和均匀分散(除了3wt%f-GONP出现重新堆叠)。相同含量下复合材料的热导率遵循如下规律:r-GONP/环氧树脂复合材料f-GONP/环氧树脂复合材料环氧树脂;Tg遵循如下规律:r-GONP/环氧树脂复合材料环氧树脂f-GONP/环氧树脂复合材料。通过纳米压痕法证明了 r-GONP与环氧树脂之间具有更强的界面结合作用;热膨胀系数测定和热重分析结果表明了 r-GONP/环氧树脂复合材料的热稳定性更高。因此,层数较多的r-GONP使环氧树脂复合材料获得了更优异的热性能。
[Abstract]:In recent years, with the rapid development of portable and wearable electronic devices towards small size functions to further promote the high power density of integrated circuits, electronic components to ensure the long time reliable operation, effective management of the heat circuit has become a key. The graphene material has excellent thermal and mechanical properties, is widely used in to improve the thermal properties of polymer composites for electronic packaging, but the thermal properties of composite materials with excellent properties of graphene are still based on material produced by the expected far, therefore the thermal properties of composite materials has greatly improved space. In this paper, graphene oxide materials (Graphene oxide, GO) as thermal conductive filler and with epoxy resin as matrix material, the effect of GO on the curing reaction of the polymer matrix, put forward to further improve the GO/ polymer composites by thermal performance Methods analyze GO materials to improve the thermal properties of polymer matrix and reinforcing mechanism of thermal stability. The main research contents and conclusions are as follows: (1) prepared by in situ solidification method (0.5,1,2,2.2,2.5,3wt%) multilayer graphene oxide (Multi-layer graphene, oxide, MGO) / epoxy resin composites. The results show that the thermal conductivity of 2wt%MGO the composite material was the biggest, is 2.03 times of pure epoxy resin. The study found that the activation energy of real-time 2wt%MGO heat conduction chain stage of curing barrier increased dramatically but also based on the curing degree of epoxy resin composite material is also increased, but the difference in the degree of cure after aging or heat after annealing will disappear, this shows that a large number of from the 2wt%MGO guide -OH for isolated hotlinked, remaining trapped / epoxy molecules break barrier epoxy molecules -MGO reaction provides a key driving force for the MGO special. The layered structure, proposes an improved shrinking core model used to explain the changes in resistance reaction in the epoxy molecule -MGO. The results showed that intercalation crosslinking reaction by promoting the conducive to further improve the thermal conductivity of the composites, but the reaction resistance gradually. According to the research, put forward a the curing reaction process optimization method for promoting the intercalation of cross-linking reaction, the results of the study show that only by postprocessing can improve the temperature of 30 DEG C to further improve the thermal conductivity of the composites, 2.96 times of pure epoxy resin. (2) a series of graphene oxide nanosheets were synthesized by in situ solidification method (Graphene oxide nanoplatelet, GONP) / epoxy resin composite material, two kinds of GONP (r-GONP and f-GONP, with a diameter similar) morphology, SOFGs, dispersion / stripping state in the matrix, circles The thermal conductivity strength of epoxy resin composite material, and the effect of Tg size / structure thermal stability. The results show that r-GONP (34nm thick) surface is smooth, a relatively rigid sheet, and f-GONP (7Nm thick) surface wrinkle downs, a flexible gossamer; r-/f-GONPs in different content can be in the the matrix is further stripped and dispersed (except 3wt%f-GONP re stack) the same content. The thermal conductivity of the composites follow the following rules: r-GONP/ f-GONP/ epoxy resin epoxy resin composite epoxy resin; Tg follow the following rules: r-GONP/ epoxy resin composite epoxy resin f-GONP/ epoxy resin composite materials by nano indentation method that. The combination has a stronger effect between r-GONP and epoxy resin interface; coefficient of determination and thermal analysis results show that the r-GONP/ epoxy resin composite thermal expansion The thermal stability of the material is higher. Therefore, the more layers of r-GONP make the epoxy resin composite better thermal performance.

【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ323.5;TB332

【相似文献】