苯乙烯系聚合物导电复合材料的制备与性能研究

发布时间：2018-03-20 02:40

本文选题：石墨烯纳米片　切入点：碳纳米管　出处：《安徽大学》2017年硕士论文　论文类型：学位论文

【摘要】：填充型复合导电塑料是一种理想的抗静电、电磁屏蔽材料,广泛应用于便携式电源、塑料芯片、机器人、显示器、生命科学、航天和太阳能等领域,被认为是最有发展前景的高分子材料之一。石墨烯纳米片(GNF),由于它独特的二维结构,使得GNF在光学、热学、电学、力学等方面都具备优异的性能,成为近年来的研究热点。相比碳纳米管(CNT),GNF具有更大的比表面积,因此,GNF在很多方面的性能优于CNT。本文分别以聚苯乙烯(PS)和聚丙烯腈-苯乙烯共聚物(AS)、聚丙烯腈-丁二烯-苯乙烯共聚物(ABS)为基体,以GNF和CNT为导电填料,采用溶液混合法制备了一系列导电复合材料,通过研究发现:PS复合材料中,CNT与基体相容性稍差,相界面明显,有明显pull-out效应;GNF与聚苯乙烯的相容性较好,填料与基体结合紧密,形成了良好的互穿网络结构。两种填料加入基体后,都使体系的粘度(η*)、储能模量(G')和损耗模量(G")随填料量的增大而上升,GNF填充的复合材料具有较好的流变行为。通过导电性能分析发现,两种填料都在1.0 vol.%达到逾渗阈值,2.0 vol.%之后电导率基本稳定,PS/CNT复合材料电导率最高达到0.1S/m,而PS/GNF复合材料最高达到0.16 S/m。PS/GNF复合材料表现出较好的力学性能和导热性能,当填料量为5vol.%时,PS/GNF复合材料的热导率高达0.88W/(m·K),而PS/CNT复合材料只有 0.56W/(m·K)。在AS复合材料体系中,由于AS的极性作用使之与填料表面的基团发生相互作用,两种填料均表现出较好的相容性,填料与基体结合紧密,分散均匀。由于AS与PS相似的结构特性,两者表现出及其相似的流变特性。由于强相互作用,两种填料都在0.5vol.%达到导电逾渗阈值,2.0 vol.%之后随填料量的加入电导率变化很小,填料量为5.0 vol.%时,AS/CNT复合材料的电导率最高达到0.14 S/m,而AS/GNF复合材料的电导率为0.154 S/m。由于GNF巨大的比表面积优势,当填料量为5vol.%时,AS/GNF复合材料的热导率高达0.88W/(m·K),而AS/GNF复合材料只有0.44 W/(m·K)。随填料量的增加复合材料的拉伸强度先减小后增大,冲击强度出现相反变化趋势,AS/CNT复合材料表现出更好的力学性能。在ABS复合材料体系中采用了溶液混合法和熔融共混法相对比,SEM结果表明,利用溶液混合法制得的样品,填料分散更好,CNT与ABS基体相容性较好,相界面模糊。GNF剥离得比较充分,均匀的穿插到基体中。溶液法所得样品更高的粘度(η*)、储能模量(G')、和损耗模量(G"),频率依赖性较低。溶液法所制得的样品具有更高的电导率,在3vol%时,两种方法所得ABS/CNT复合材料的电导率相差3个数量级。在2 vol.%时,溶液法所得ABS/GNF复合材料的热导率为0.62 W/(m·K),而熔融共混法所得ABS/GNF复合材料的热导率仅有0.47 W/(m·K)。熔融混合法所得的样品均表现出较好的力学性能和热稳定性。
[Abstract]:Filled composite conductive plastic is an ideal antistatic, electromagnetic shielding material, widely used in portable power supply, plastic chips, robots, monitors, life sciences, aerospace and solar energy, etc. It is considered to be one of the most promising polymer materials. Because of its unique two-dimensional structure, GNF has excellent optical, thermal, electrical and mechanical properties. It has become a hot research topic in recent years. Compared with CNT, GNF has a larger specific surface area. In this paper, polyacrylonitrile-styrene copolymers, polyacrylonitrile-butadiene-styrene copolymers and polyacrylonitrile-butadiene-styrene copolymers were used as matrix and GNF and CNT as conductive fillers, respectively. A series of conductive composites were prepared by solution mixing method. It was found that the compatibility between pull-out and matrix was slightly poor, the phase interface was obvious, and the compatibility between pull-out and polystyrene was obvious. A good interpenetrating network structure is formed. When the two fillers are added to the matrix, The viscosity (畏 _ (n), energy storage modulus (G _ (O)) and loss modulus (G ")) of the composites increased with the increase of filler content, and the rheological behavior of the composites filled with GNF was better than that with the increase of filler content. It was found from the analysis of electrical conductivity that the composites had good rheological behavior. The conductivity of PS- / CNT composites reached 0.1 S / m and that of PS/GNF composites reached 0.16 S / m.PS- / GNF composites with good mechanical properties and thermal conductivity after reaching the percolation threshold of 1.0 vol.% and 2.0 vol.%. When the filler content is 5 vol.%, the thermal conductivity of PS- / GNF composite is up to 0.88 W / m 路KN, while that of PS/CNT composite is only 0.56 W / m 路Ke. In as composite system, as polarity makes it interact with the group on the filler surface. Both kinds of fillers exhibit good compatibility, and they are closely bound to the matrix and dispersed uniformly. Due to the similar structural characteristics of as and PS, the two fillers exhibit similar rheological properties, and because of the strong interaction, the two fillers exhibit similar rheological properties. The conductivity of both kinds of fillers changed little with the addition of fillers, when the conductivity of both fillers reached the percolation threshold of 0.5 vol.% and 2.0 vol.%. When the filler is 5.0 vol.%, the electrical conductivity of AS-CNT composites is 0.14 S / m, while that of AS/GNF composites is 0.154 S / m. Due to the large specific surface area advantage of GNF, The thermal conductivity of AS-GNF composites is up to 0.88 W / m 路K ~ (-1), while that of AS/GNF composites is only 0.44 W / m 路K ~ (-1). The tensile strength of AS-GNF composites decreases first and then increases with the increase of filler content. The impact strength of AS-CNT composites showed a reverse trend. The results of solution mixing method and melt blending method in ABS composites showed that the samples obtained by solution mixing method showed better mechanical properties. The better the dispersion of filler is, the better the compatibility between CNT and ABS matrix is, and the fuzziness of phase interface. The samples obtained by the solution method have higher viscosity (畏 _ (n), storage modulus (G ~ (+)), and loss modulus (G "), lower frequency dependence. The samples prepared by the solution method have higher electrical conductivity, and the samples obtained by the solution method have higher electrical conductivity at 3 volg%. The conductivity of ABS/CNT composites obtained by the two methods is 3 orders of magnitude difference. The thermal conductivity of ABS/GNF composites obtained by solution method was 0.62 W / m 路KN, while that of ABS/GNF composites obtained by melt blending method was only 0.47 W / m 路KN. The samples obtained by melt mixing method showed good mechanical properties and thermal stability.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ324.8;TB332

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