高介电常数氰酸酯树脂基复合材料的研究

发布时间：2018-03-14 14:22

本文选题：石墨烯　切入点：聚离子液体　出处：《苏州大学》2016年硕士论文　论文类型：学位论文

【摘要】：高介电常数材料是当今功能材料领域的研究热点之一,其在电子元器件、机械、航空航天和生物医学等领域具有巨大的应用价值。相对于传统的高介电常数无机材料,聚合物基复合材料以其轻质、良好的工艺性和韧性而受到了广泛关注。近年来,最为热门的碳导体材料以其独特的纳米结构和优异的导电性在高介电复合材料研究方面具有无比巨大的前景。然而,纳米碳材料在作为功能体加入树脂基体中时,若不进行表面处理,则存在非常明显的团聚现象。另一方面,离子容易被禁锢在交联固化树脂当中而无法迁移,若离子液体在树脂基体中形成微相分离乃至双连续相,构成离子导通通道,此时的复合材料将会具有改善的离子电导率,复合材料将会有更好的介电性能。本文的研究工作主要包括以下两部分。首先,我们成功合成了新型环氧基功能化离子液体(e-VimiBF4)并通过π阳离子-π相互作用制备了一种新型的聚离子液体/石墨烯杂化体(PIL-TrGO)。使PIL成功负载于TrGO表面,石墨烯杂化体保持了TrGO优异的电导率(10-2S/cm),在此基础上将PIL-TrGO杂化体加入到氰酸酯(CE)树脂中,制备了PIL-TrGO/CE复合材料,系统研究了复合材料的介电性能。研究结果表明,与TrGO/CE复合材料相比,PIL-TrGO/CE复合材料的介电性能更为优异。在接近复合材料渗流阈值(fc)时,100Hz下,1PIL-TrGO/CE复合材料的介电常数和介电损耗分别为0.6TrGO/CE复合材料的13倍和0.57倍,三元复合材料的渗流阈值也仅只有0.94wt%。三元复合材料较高的介电常数是由于所制得的PIL-TrGO杂化体在复合材料中具有很好的分散性和相容性,且杂化体中PIL表层上的环氧基官能团可以与CE发生共聚反应,增加了PIL-TrGO杂化体在树脂基体中的分散稳定性,从而大大增加了复合材料中微电容结构。此外,高极性的PIL包覆层可以引入更多的极性界面,增加了Maxwell-Wagner-Sillars(MWS)极化作用。而较低的介电损耗是由于电子绝缘的PIL存在于石墨烯表面,阻碍了电子导通通道的形成。其次,研究了复合材料中离子电导对其介电性能的影响。设计制备了具有分相结构的PIL/CE复合材料,并在复合材料中引入锂盐,利用锂离子的高电荷迁移率,制备了Li+/PIL/CE高介电常数复合材料,并对其进行了系统研究。研究结果表明随着PIL含量的增大,复合材料中出现了微相分离;PIL相在基体中均匀分散,且相畴大小在200nm-500nm左右。所制备的Li+/PIL/CE三元复合材料具有较优的介电性能,100Hz下10Li+/PIL/CE的介电常数是10PIL/CE二元复合材料的6.6倍,三元复合材料的电容值在较大频率范围(102-106Hz)内也比10PIL/CE复合材料高出将近一个数量级。这是由于环氧基功能化的PIL可以与CE树脂发生共聚反应,微相分离的PIL相在CE树脂基体中具有优良的分散性,可以形成大量的界面区域。此外,Li+也可以在PIL相中通过跳跃机制和聚合物长链的链段运动形成离子电导,使得MWS界面极化作用显著增强。正负电荷可以在PIL相表面富集,在树脂基体中并形成大量以PIL为电极、CE为电介质的微电容结构,有利于其作为储能电容器方面的应用。
[Abstract]:The high dielectric constant material is one of the research hotspot in the field of functional material, its mechanical in electronic components, and has great application value in aerospace and biomedical fields. Compared with the traditional high permittivity inorganic materials, polymer composite materials such as lightweight, technology and good toughness and has attracted extensive attention. In recent years, the most popular carbon conductor material with its unique nano structure and excellent electrical conductivity has a very great prospect in high dielectric composite materials research. However, the carbon nano material in the body as a function of adding resin matrix, without surface treatment, there is a very obvious phenomenon of agglomeration on the other hand, ion is easy to be imprisoned and unable to migrate in curing resin, if the ionic liquid in the resin matrix and the formation of micro phase separation of double continuous phase, an ion channel, The composite material will have improved ionic conductivity of the composite material will have better dielectric properties. The main research work of this paper includes the following two parts. Firstly, we successfully synthesized a new type of epoxy group functionalized ionic liquid (e-VimiBF4) and the PI cation pi interaction for preparation of a novel poly ion the liquid / graphene hybrid (PIL-TrGO). PIL has successfully loaded on the surface of the TrGO graphene hybrid maintains excellent conductivity of TrGO (10-2S/cm), based on PIL-TrGO hybrid into cyanate ester (CE) resin, PIL-TrGO/CE composite materials were prepared and studied the dielectric properties of the composite materials research results show that compared with TrGO/CE composites, the dielectric properties of PIL-TrGO/CE composites is more excellent. The composite near the percolation threshold (FC), 100Hz, 1PIL-TrGO/, CE composite dielectric constant The number and dielectric loss of 0.6TrGO/CE composite materials were 13 times and 0.57 times the percolation threshold of the composites is only three yuan only three yuan 0.94wt%. the dielectric constant of composites is higher because the PIL-TrGO hybrids were prepared with dispersion and good compatibility in the composite material, and epoxy group hybrid PIL surface can be copolymerized with CE, increase the dispersion and stability of PIL-TrGO hybrids in the resin matrix, thereby greatly increasing the micro capacitance structure in composite materials. In addition, the high polarity of the PIL coating layer can introduce more polar interface, increased Maxwell-Wagner-Sillars (MWS) polarization. The low dielectric loss is due to electrical insulation of PIL exist in the surface of graphene, hindered the formation of electronic conduction channel. Secondly, study the effect of ionic conductivity of composite materials on its dielectric properties. PIL/CE composite materials with phase structure were prepared, and the introduction of lithium in composite materials, high charge mobility using lithium ion, Li+/PIL/CE high dielectric constant of the composite material was prepared, and has carried on the system research. The results show that with the increase of PIL content, the composite in the micro phase separation; dispersed phase in PIL matrix, and the domain size is about 200nm-500nm. The three element composite material prepared by Li+/PIL/CE has better dielectric properties, the dielectric constant of 10Li+/PIL/CE 100Hz is 6.6 times the two yuan 10PIL/CE composite, three element composite capacitance value in a wide frequency range (102-106Hz) also than 10PIL/CE composites by nearly an order of magnitude. This is due to the epoxy functionalized PIL can be copolymerized with CE resin, the microphase separation of PIL phase in CE resin with excellent dispersibility, Can be formed of a large area of the interface. In addition, Li+ can also be formed by ion conductance in PIL phase jump mechanism and long chain polymer chain segment movement, makes the MWS interface polarization significantly enhanced. The positive and negative charges in the PIL phase surface enrichment, in the resin matrix and the formation of a large number of PIL electrode, CE micro capacitor structure the dielectric, which is favorable for application of energy storage capacitors.

【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB332

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