Advances in Epoxy/Graphene Nanoplatelet Composite with Enhanced Physical Properties: A Review

In this review, development from graphene nanoplatelet, that is, comprised of short bulk of single layer graphene, into modified-polymer/graphene nanoplatelet composite is presented. Preparation methods of graphite, graphene, and graphene nanoplatelets have also been discussed. Graphene nanoplatelet and modified graphene nanoplatelet commend unique properties to composites such as excellent thermal and electrical conductivity as well as mechanical and barrier properties. Graphene nanoplatelet fabrication techniques by solution mixing, melt blending, and in situ polymerization are also discussed. Excellent dispersion of nanoplatelets in polymer/graphene nanoplatelet depends upon the selection of suitable fabrication technique. Moreover, the corresponding significance, exploitation, challenges, and future aspect of polymer/graphene nanoplatelet-based material is overviewed.     

Perspectives of Epoxy/Graphene Oxide Composite: Significant Features and Technical Applications

In this article, advancement in epoxy/graphene oxide composites is presented. These materials are comprised of graphene oxide (GO) as filler (carbon-based material, thermodynamically stable, two-dimensional, planar and layered structure). Due to improved properties (mechanical response, low density, electrical resistance, and thermal stability), epoxy resins are used in several applications. Graphene oxide proposes unique properties to epoxy composites as high surface area, thermal and electrical conductivity as well as mechanical and barrier properties, relative to neat matrix. The corresponding significance of epoxy/GO-based materials, related challenges, and potential exploitation regarding technical applications (aerospace, gas sensor, electronic devices, etc.) have been overviewed.     

Exploration of Epoxy Resins,Hardening Systems,and Epoxy/Carbon Nanotube Composite Designed for High Performance Materials: A Review

Epoxy resins, is an important class of reactive polymers, have been reported to be toughened by nanoparticles. Carbon nanotube is a tubular cylinder ofcarbonatoms having extraordinary mechanical, electrical, and thermal properties. In this article, present state of epoxy/carbon nanotube composite is given. Types of epoxy and hardening agents commonly used in composite processing have been thrashed out. Frequently used fabrication techniques are discussed with particular emphasis on evaluating dispersion state of nanotube. Epoxy/carbon nanotube composites offer substantially improved properties compared to traditional fiber-reinforced epoxy composites. Finally, potential relevance for efficiently transforming filler properties to matrix facilitating aerospace relevance is conversed.     

Graphene Oxide as a Prospective Graft in Polyethylene Glycol for Enhancing the Toughness of Epoxy Nanocomposites

Polyethylene glycol (PEG) was successfully grafted onto the surface of graphene oxide (GO) by the “grafting to” technique. PEG, GO as well as the PEG grafted GO (GO-g-PEG) was successfully incorporated into an epoxy matrix and subsequently cured using diethylenetoluenediamine (DETDA) to make epoxy nanocomposites. Mechanical, thermal, and rheological properties of the epoxy nanocomposites were studied to check the effectiveness of these fillers in the epoxy matrix. An improvement of 255% and 334% at a very low filler loading of about 0.1 wt% was observed in the fracture toughness of GO and GO-g-PEG loaded systems versus the neat epoxy. Toughening mechanisms are also explained by analyzing SEM images of the fractured surface. Modeling of rheological properties was carried out by following time-independent Newtonian model. The homogeneity of the epoxy filler systems are explained with the help of Cole–Cole plots. The thermal stability of the filler loaded epoxy composites was examined in detail by TGA. Improvements in mechanical properties reveal the potential benefit of the grafting process in epoxy toughening. POLYM. ENG. SCI., 60:773–781, 2020. © 2020 Society of Plastics Engineers     

石墨烯/陶瓷基复合材料研究进展

2004年以来,石墨烯以其优异的力学、电学、热学和光学性能以及独特的二维结构成为材料领域的研究热点。本文结合作者所在课题组的相关工作,综述了石墨烯应用于陶瓷基复合材料的国内外研究进展,重点介绍了石墨烯/陶瓷复合粉体的制备、石墨烯/陶瓷基复合材料的烧结工艺以及性能,探讨了石墨烯/陶瓷基复合材料的研究发展方向及应用前景。     

Epoxy Resin Composite Reinforced with Carbon Fiber and Inorganic Filler: Overview on Preparation and Properties

Among carbon fillers, carbon fiber is considered to be an ideal reinforcement for epoxy because of its outstanding electrical, mechanical, and thermal features. Several inorganic fillers such as zinc oxide, titania, and silica are also used in epoxy matrix for property enhancement. The review initially focuses the preparation methods and physical characteristics of epoxy/carbon fiber composite. Afterward, fabrication and properties of epoxy/zinc oxide/titania/silica composites are also conversed. Moreover, the effect of filler dispersion on polymer properties’ improvement is also highlighted. Epoxy/carbon fiber composites are employed more frequently and effectively in defense-related applications compared with epoxy/inorganic nanofiller composite.     

Recent Developments in Different Types of Flame Retardants and Effect on Fire Retardancy of Epoxy Composite

In this review, main focus is on the different types of fire retardants, their properties, and pertinent potential. Both inorganic (titania, silica, and zinc oxide) and organic (graphite, graphene, and graphene nanoplatelet) compounds have been discussed as flame inhibitors. Among various sorts of fire retardants, halogen-based flame inhibitors possess outstanding features. Consequently influence of fire retardant on the performance of epoxy composite has been discussed. It was noted that significant enhancement occurs by addition of organic and inorganic fillers in epoxy matrix. However, halogen additives impart better flame resistance to epoxy composite. Toward the end of this review, potential of halogen-containing fire retardant is discussed.     

Graphene/carbon black/natural rubber composites prepared by a wet compounding and latex mixing process

The extensively used latex mixing approach to prepare graphene can improve the graphene dispersion but meets some challenges in the preparation of high content carbon black filled rubber system like a rubber tire. Owing to the high melt viscosity of the rubber/graphene masterbatch, the dispersion of carbon black is not perfect during twin-roll mixing and some aggregates will be formed. Here we proposed a wet compounding process, combined with ultrasonically assisted latex mixing, named as the WCL method to prepare reduced graphene oxide/carbon black/natural rubber (rGO/CB/NR) composites. The morphological observations confirmed that both graphene and carbon black can be evenly dispersed in the rubber composites. The incorporation of rGO also improves the hardness, thermal conductivity and anti-aging properties of the composites. The rGO/CB/NR composites prepared by the WCL method possess better mechanical properties compared to conventional latex mixing. The entanglement-bound rubber tube model was utilised to understand the reinforcing mechanism.     

快速固化环氧树脂/碳纤维复合材料的性能

利用差示扫描量热分析仪研究了一种快速固化环氧树脂体系的固化工艺参数,确定了以真空辅助树脂灌注工艺制备快速固化环氧树脂/碳纤维复合材料的成型方法,并与常规固化环氧树脂体系制备的碳纤维复合材料进行对比,采用傅里叶变换红外光谱仪对两种材料的树脂基体进行了分析,考察了两种复合材料的纤维含量、孔隙率及力学性能,最后通过扫描电子显微镜观察了快速固化树脂基体与碳纤维的界面结合性。结果表明,快速固化树脂在99℃下固化6 min后固化度可达96%,能够大幅缩减碳纤维复合材料的成型时间,以其制备的碳纤维复合材料拉伸强度比常规固化环氧树脂复合材料高11.20%,弯曲强度高16.92%,纵横剪切强度高7.44%,快速固化树脂与碳纤维界面结合性良好。     

Effects of Fortifier on Glass/Carbon Fiber Reinforced Tetrafunotional Epoxy Resin

Glass fiber reinforced epoxy composites were prepared using tetra-N-glycidyl-p,p′-diaminodiphenyl methane (TGDDM) as a resin matrix with/without fortifier PGEHA/VCDRC (at 20 phr level) using DDM/DDS as curing agent; the composites were evaluated for their various physical, mechanical, chemical, and electrical properties. Carbon fiber (i.e., unidirectional, bidirectional, and chopped) reinforced composites of TGDDM with/without epoxy fortifier PGEHA/VCDRC (at 20 phr level) were also prepared and evaluated for their physical and some mechanical and chemical properties. It is observed that incorporation of fortifier (at 20 phr level) improves these properties significantly.     

Mechanical and Anticorrosive Properties of Graphene/Epoxy Resin Composites Coating Prepared by in-Situ Method

The graphene nanosheets-based epoxy resin coating (0, 0.1, 0.4 and 0.7 wt %) was prepared by a situ-synthesis method. The effect of polyvinylpyrrolidone/reduced graphene oxide (PVP-rGO) on mechanical and thermal properties of epoxy resin coating was investigated using nanoindentation technique and thermogravimetric analysis, respectively. A significant enhancement (ca. 213% and 73 °C) in the Young modulus and thermal stability of epoxy resin coating was obtained at a loading of 0.7 wt %, respectively. Furthermore, the erosion resistance of graphene nanosheets-based epoxy resin coating was investigated by electrochemical measurement. The results showed also that the Rrcco (ca. 0.3 mm/year) of graphene nanosheets-based epoxy resin coating was far lower than neat epoxy resin (1.3 mm/year). Thus, this approach provides a novel route for improving erosion resistance and mechanical-thermal stability of polymers coating, which is expected to be used in mechanical-thermal-corrosion coupling environments.     

Physicomechanical Properties of Carbon Fiber Reinforced Epoxy Composites

Fabrication of carbon fiber reinforced epoxy composites from the matrix resins diglycidyl ether of bisphenol-A (DGEBA) and tetraglycidyl bis(aminotolyl) cyclohexane (TGBATC) using 4,4′-diaminodiphenyl methane (DDM) as curing agent. The composites were evaluated for their physical and mechanical properties. A significant improvement in the properties was observed on addition of 20 phr of an epoxy fortifier.     

微波技术在环氧树脂及其复合材料中的应用

论述了近年来微波固化技术在环氧树脂及其复合材料固化中的应用,重点比较了微波固化与传统热固化后环氧树脂及其复合材料的力学性能、热性能和粘结强度的变化,并对环氧树脂复合材料微波固化的研究进行了展望。     

Effect of Functionalized Graphene with Modified Clay on Flammability of Copper Clad Laminated Novolac Cured Epoxy Composites

In this work, we prepared epoxy composites and a copper clad laminates (CCLs) by an introduction of modified clay with graphene to a novolac cured epoxy resin to improve the thermo-mechanical and flame retardant properties. Further, the typical important properties of synthesized CCLs were investigated. The incorporation of surface modified organographene (OG) and organomodified clay with suitable concentration can noticeably increase the storage modulus, crystallinity, the heat distortion temperature, and flame retardant of the CCLs. Moreover, these results suggest the potential of the epoxy composites for the printed circuit such as high speed IC boards.     

石墨烯改性环氧锌基防腐涂料的制备与性能研究

针对传统环氧富锌涂料环保性差、质量大、成本高等问题,利用石墨烯优异的导电性与独特的二维片层结构可增强涂层防腐性能的特性,取代传统环氧富锌涂料中的部分锌粉,以期制备低锌含量的石墨烯环氧锌基涂料。首先将石墨烯材料与环氧树脂预混合,掺杂天然高分子表面活性剂,制备一种高分散性石墨烯 /环氧树脂浆料;然后将其与计量的环氧树脂、锌粉、其他功能颜填料复配,通过高速分散与砂磨的制备方式相结合,得到石墨烯改性环氧锌基防腐涂料;最后通过力学性能、连接强度、交流阻抗、耐中性盐雾等方法探索涂层关键性能。研究结果表明：该石墨烯涂层防腐性能优异, 2 000 h盐雾划痕腐蚀扩展 0.9 mm,且力学性能与施工性能好,可广泛应用于船舶、海工设备、桥梁等大型钢结构装备领域。     

EP/氧化石墨烯–硬脂酸丁酯微胶囊复合材料

采用种子微悬浮聚合法制备了聚苯乙烯/氧化石墨烯复合囊壁包覆硬脂酸丁酯微胶囊润滑材料(MGO–Micro LMs),以MGO–Micro LMs为润滑填料,环氧树脂(EP)为基体材料,采用浇注成型工艺制备了EP/MGO–Micro LMs复合材料。采用滑动摩擦磨损试验仪评价了MGO–Micro LMs对EP基体材料摩擦学性能的影响;采用扫描电子显微镜对磨损面的微观形貌进行表征,并探究了其磨损机理。结果表明,MGO–Micro LMs能够显著地降低EP的摩擦系数和磨损量,当MGO–Micro LMs质量分数为20%时,EP/MGO–Micro LMs复合材料的摩擦系数为0.138 44,磨损量减少了约42.3%,磨损机理主要为磨粒磨损。     

偶联剂在环氧树脂／纳米SiO2复合材料中的应用

采用偶联剂、通过原位分散聚合法制得了环氧树脂／纳米二氧化硅（ｎａｎｏ－ＳｉＯ２）复合材料。探讨了偶联剂的用量对复合材料性能的影响,利用拉伸试验、冲击试验、扫描电镜、热失重分析等方法研究了加与不加偶联剂的复合材料的结构和性能。结果表明：在偶联剂的作用下,ｎａｎｏ－ＳｉＯ２较均匀地分散在环氧树脂基体中,有效地增加了环氧树脂的强度及韧性,并提高了环氧树脂的耐热性。     

Epoxy composites with carbon nanotubes and graphene nanoplatelets – Dispersion and synergy effects

Carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) at different mix ratios were dispersed by ultrasonication into an epoxy matrix and the effects of CNT:GNP ratios on the mechanical and electrical properties of the hybrid composites were investigated. The combination of CNT and GNP in a ratio 8:2 was observed to synergistically increase flexural properties and to reduce the electrical percolation threshold for the epoxy composites, indicating easier formation of a conductive network due to the improved state of CNT dispersion in the presence of GNPs. The state of dispersion was evaluated at different length scales by using optical microscopy, UV–Vis spectroscopy, rheological measurements, scanning electron microscopy, transmission electron microscopy and sedimentation tests. The Fourier transform infrared spectra for CNT and GNP indicate that the GNPs contain oxygen moieties responsible for better interactions with the epoxy matrix.     

Improving delamination resistance of carbon fiber reinforced polymeric composite by interface engineering using carbonaceous nanofillers through electrophoretic deposition: An assessment at different in-service temperatures

In this article, modification of carbon fiber surface by carbon based nanofillers (multi-walled carbon nanotubes [CNT], carbon nanofibers, and multi-layered graphene) has been achieved by electrophoretic deposition technique to improve its interfacial bonding with epoxy matrix, with a target to improve the mechanical performance of carbon fiber reinforced polymer composites. Flexural and short beam shear properties of the composites were studied at extreme temperature conditions; in-situ cryo, room and elevated temperature (−196, 30, and 120°C respectively). Laminate reinforced with CNT grafted carbon fibers exhibited highest delamination resistance with maximum improvement in flexural strength as well as in inter-laminar shear strength (ILSS) among all the carbon fiber reinforced epoxy (CE) composites at all in-situ temperatures. CNT modified CE composite showed increment of 9% in flexural strength and 17.43% in ILSS when compared to that of unmodified CE composite at room temperature (30°C). Thermomechanical properties were investigated using dynamic mechanical analysis. Fractography was also carried out to study different modes of failure of the composites.     

环氧树脂/碳纳米管复合材料制备及导电性能研究进展

简要介绍了环氧树脂/碳纳米管复合材料的组成以及碳纳米管在环氧树脂中的分散方法;综述了环氧树脂/碳纳米管复合材料的制备方法,包括溶液浇铸法、原位聚合法、化学改性法、混合固化剂辅助叠层法和树脂传递模塑法;总结了国内外对环氧树脂/碳纳米管复合材料导电性能的研究现状,并分析了影响其导电性能的因素,包括碳纳米管的比表面积、表面功能化和制备方法,剪切速率及固化条件等。