A review of the research and advances in electromagnetic joining of fiber‐reinforced thermoplastic composites

The demand for polymer composites in structural and nonstructural applications has expanded rapidly due to their lightweight, high strength, and stiffness characteristics. Joining of polymer composite is not an easy task as inadequate joint strength leads to failure of a structure due to stress concentration. The following are the three basic methods available for joining of thermoplastic composites: adhesive joining, mechanical fastening, and fusion bonding. Electromagnetic joining is a class of fusion bonding where electromagnetic force is used for generation of heat. Electromagnetic joining has gained new interest among the research fraternity with the development of thermoplastic composites. This type of joining or welding technique offers many advantages over other joining techniques. This joining technique can be used for assembly as well as repairing of thermoplastic polymer‐based composites parts. The main aim of this article is to review the different electromagnetic joining methods for thermoplastic composites and present the recent developments in this area. The electromagnetic joining methods such as induction welding, microwave welding, and resistance welding have been comprehensively discussed in the context of their applicability for joining of thermoplastic polymer‐based composites. POLYM. ENG. SCI., 59:1965–1985, 2019. © 2019 Society of Plastics Engineers     

Effect of Interface Structure on Mechanical Properties of Advanced Composite Materials

This paper deals with the effect of interface structures on the mechanical properties of fiber reinforced composite materials. First, the background of research, development and applications on hybrid composite materials is introduced. Second, metal/polymer composite bonded structures are discussed. Then, the rationale is given for nanostructuring the interface in composite materials and structures by introducing nanoscale features such as nanopores and nanofibers. The effects of modifying matrices and nano-architecturing interfaces on the mechanical properties of nanocomposite materials are examined. A nonlinear damage model for characterizing the deformation behavior of polymeric nanocomposites is presented and the application of this model to carbon nanotube-reinforced and reactive graphite nanotube-reinforced epoxy composite materials is shown.     

Review on adhesive joints and their application in hybrid composite structures

Composites have been used extensively in various engineering applications including automotive, aerospace, and building industries. Hybrid composites made from two or more different reinforcements show enhanced mechanical properties required for advanced engineering applications. Several issues in composites were resolved during the last few years through the development of new materials, new methods and models for hybrid joints. Many components in automobile are joined together either by permanent or temporary fastener such as rivets, welding joint and adhesively bonded joints. Increasing use of bonded structures is envisaged for reducing fastener count and riveted joints and there by drastically reducing assembly cost. Adhesive bonding has been applied successfully in many technologies. In this paper, scientific work on adhesively bonded composites and hybrid composites are reviewed and discussed. Several parameters such as surface treatment, joint configuration, material properties, geometric parameters, failure modes, etc. that affect the performance of adhesive bonded joints are discussed. Environmental factors like pre-bond moisture and temperature, method of adhesive application are also cited in detail. A specific case of adhesive joints in hybrid bonded-bolted joints is elaborated. As new applications are expanding in the field of composites joining and adhesive joints, it is imperative to use information on multiple adhesives and their behaviour in different environmental conditions to develop improved adhesive joint structure in mechanical applications.     

High Thermal Conductivity Polymer Composites Fabrication through Conventional and 3D Printing Processes: State-of-the-Art and Future Trends

The lifespan and the performance of flexible electronic devices and components are affected by the large accumulation of heat, and this problem must be addressed by thermally conductive polymer composite films. Therefore, the need for the development of high thermal conductivity nanocomposites has a strong role in various applications. In this article, the effect of different particle reinforcements such as single and hybrid form, coated and uncoated particles, and chemically treated particles on the thermal conductivity of various polymers are reviewed and the mechanism behind the improvement of the required properties are discussed. Furthermore, the role of manufacturing processes such as injection molding, compression molding, and 3D printing techniques in the production of high thermal conductivity polymer composites is detailed. Finally, the potential for future research is discussed, which can help researchers to work on the thermal properties enhancement for polymeric materials.     

A review on direct assembly of through‐the‐thickness reinforced metal–polymer composite hybrid structures

Constant efforts to reduce the structural weight of transportation systems as a solution to control emission levels are currently shaping the way modern cars and airplanes are designed and manufactured. Increased attention has been given to innovative metal–composites multi‐material concepts for the production of lightweight structures. However, the nature of these very dissimilar materials makes their joining a rather complicated task. Recently several technologies have been proposed to overcome process limitation and increase the load transfer between metal and composite in hybrid structures. One of the promising solutions is a new concept known as direct assembling with through‐the‐thickness reinforcements. In this concept, the composite material of a hybrid joint is directly assembled upon a surface‐structured metallic part. Features structured on the metallic part, by a manufacturing phase, act as a through‐the‐thickness reinforcement improving the out‐of‐plane strength and load transfer capabilities of such joints. The current status and state‐of‐art direct assembling technologies are reviewed in this article. Examples of reviewed metal structuring techniques include micromachining, stamping, Surfi‐Sculpt, additive manufacturing, cold metal transfer, and metal injection molding structuring. Direct assembling techniques addressed in this article are vacuum‐assisted resin infusion, resin transfer molding, prepreg/autoclave assembly, and ultrasonic joining. POLYM. ENG. SCI., 59:661–674, 2019. © 2018 The Authors. Polymer Engineering & Science published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers.     

A review on synthetic strategies and gas sensing approach for polypyrrole-based hybrid nanocomposites

Polypyrrole (PPy)-based hybrid nanocomposites of organic and inorganic hybrid materials are not restricted for academic research, but nowadays, they are useful to design innovative industrial applications such as fuel cell, solar cell, catalysts, sensors, energy, and medical applications. In recent applications, PPy and its hybrid composites have been emerged as promising sensors due to their unique physical and chemical properties. In this article, the role of PPy-based hybrid nanocomposites for the improvement in sensing applications has been discussed in detail. Along with this is the systematic discussion of the synthesis techniques of PPy sensory hybrid nanocomposites that provides a better understanding of this research area. Finally, certain limitations of PPy and its hybrid nanocomposites-based sensor are also discussed for sensing.     

Polymeric coatings for protection of historic monuments: Opportunities and challenges

The conservation and protection of historic monuments or culturally significant structures have recently attracted much attention from material scientists. This review is given of the various aspects of the monuments protection such as the main reasons of damaging and spoiling of the historical monuments, the factor of contact angle as one of the essential parameters in the selection of polymeric coatings, and some of usual types of polymeric materials used for monument protection. There has been growing interest in developing novel materials for using in protective fields. Nowadays, the polymeric coatings, especially those with high hydrophobicity, are widely used to decrease or even stop further deterioration of historical monument. This review presents some of the most well‐known polymers used as protective materials such as acrylics, alkoxysilanes, fluorinated polymers, and hybrid organic–inorganic coatings. Furthermore, hybrid organic–inorganic coatings as a new class of materials are increasingly interesting materials because of their extraordinary properties deriving from the combination of the different building blocks and it is attempted to focus on this materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Carbon-family materials for flame retardant polymeric materials

As an abundant and attractive element, the emergence of new carbon-based materials brings revolutionary development in material science and technology. Carbon-based materials have spawned considerable interest for fabricating polymer composites/nanocomposites with greatly improved mechanical, thermal, gas barrier, conductivity, and flame retardant performance. In this review, the importance of carbon-based materials and the necessity of fire resistance for polymeric materials are initially introduced. Then, the fundamental flame retardant mechanisms and experimental analytical techniques are described to understand the relationship between structures and flame retardant properties. The main section is dedicated to the preparation and properties of multifunctional polymer composites/nanocomposites with carbon-based materials, with special emphasis on the flame retardant properties of these materials. A wide variety of carbon-based materials are discussed for use in flame retardant polymer nanocomposite, including graphite, graphene, carbon nanotubes, fullerenes as well as some new emerging carbon forms (carbon nitride, carbon aerogels, etc). Finally, a brief outlook at the developments in carbon-based materials for flame retardant polymeric composites is given by discussing the major progress, opportunities, and challenges.     

钛聚合物的应用进展

钛是一种耐腐蚀性非常优良的金属材料,但是,由于钛金属材料价格昂贵,一直影响其在一般工业特别是民用工业领域的推广应用.如果将钛金属与有机高分子材料“嫁接”成合金态高聚物,再以涂层的形式推广应用到工业金属结构的防腐蚀领域,既可以替代不锈钢,解决工业腐蚀的难题,又能大大降低制造成本,提高企业的经济效益.对国内外钛聚合物的发展...     

Functional Polymeric Membrane Containing Inorganic Nanoparticle: Recent Advances and Applications

Considerable industrial and academic interest is garnered by polymer/inorganic nanoparticle composites in technical applications. In this respect, inorganic nanoparticles such as silica, titania, and zinc oxide are dispersed in polymer matrices. Tribological behavior and high-impact resistance of nanoparticles have opened new opportunities for polymeric membranes. Current article overviews research in the field of inorganic nanoparticle-reinforced polyetherimide, polyvinyl alcohol, poly(etheretherketone), polylactic acid, and polyvinyl chloride. The membranes were fabricated through distillation precipitation, solution casting, and microwave-assisted protocol. Property–structure relationship of polymer/inorganic nanoparticle membranes and potential applications in medical, fuel cell, and gas separation have been discussed.     

A study on nanofiber‐reinforced thermoplastic composites (II): Investigation of the mixing rheology and conduction properties

This article is portion of a comprehensive study on the development of nanofiber‐reinforced polymer composites for electrostatic discharge materials and structural composites. Vapor‐grown carbon fibers with an average diameter of 100 nm were used as a precursor and model fiber system for carbon nanotubes. These nanofibers were purified and functionalized to provide for an open network of high‐purity nanofibers. Banbury‐type mixing was used to disperse the nanofibers in the polymer matrix. Rheological and microscopic analysis showed that the high shear processing of the polymer/nanofiber mixture led to a homogeneous dispersion of nanofibers with no agglomerates present and no shortening of the nanofibers. The shear thinning behavior of polymeric materials helps in the mixing of the nanofibers to form the composites. A percolation threshold for electrical conduction of 9–18 wt % was observed for the highly dispersed nanofiber networks. The electrical behavior of these materials was not affected by changes in humidity. Microscopic analysis showed highly dispersed nanofibers with no indications of porosity. These conducting polymers are well suited for electrostatic discharge applications, and might well become multifunctional materials for strength/electrical applications. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1162–1172, 2001     

Carbon nanotube-based nanocomposites and their applications

The purpose of the current review article is to present a compherensive understanding regarding pros and cons of carbon nanotube–related nanocomposites and to find ways in order to improve the performance of nanocomposites with new designs. Nanomaterials including carbon nanotubes (CNTs) are employed in industrial applications such as supercapacitors, and biosensors, and etc. The present article has been prepared in three main categories. In the first part, carbon nanotube types have been presented, as single-walled carbon nanotubes, multi-walled carbon nanotubes, and also equivalent circuit models, which have been used to more clarify the experimental measurements of impedance. In the second part, nanocomposites with many carbon, inorganic and polymeric materials such as polymer/CNT, activated carbon/CNT, metal oxide/CNT, and carbon fiber/CNT have been investigated in more detail. In the third part, the focus in on the industrial applications of CNTs. including supercapacitors, biosensors, radar absorbing materials, solar cells, and corrosion protection studies. This review article explains the latest advances in carbon nanotubes and their applications in electrochemical, electrical and optical properties of nanocomposites.     

Adhesively bonded composite tubular joints: Review

The aim of this review article is to examine solutions and challenges associated with adhesively bonded fibre reinforced polymer (FRP) pipe sections. FRP materials have been used in piping systems for more than 40 years. Higher specific mechanical properties and corrosion resistance of FRP makes it a potential candidate for replacing metallic piping structures. Another advantage of FRP structures is the large number of design variables available. Despite the advantages associated with FRP structures, their application is still limited, partly due to unsatisfactory methods for joining composite subcomponents and inadequate knowledge of failure mechanisms under different loading conditions. Adhesively bonded joints are attractive for many applications, since they offer integrated sealing and minimal part count and do not require pipe extremities with complex geometries such as threads or bell and spigot configurations. Normally, an adhesive joint results in more uniform stress distribution, undamaged fibre architecture, and smooth surface contours. In the present article, a comprehensive review of various joining techniques for FRP piping through adhesive bonding is presented and damage mechanisms for different loading conditions are examined.     

Novel organic–inorganic composites with high thermal conductivity for electronic packaging applications: A key issue review

Significant progress has been made recently in developing the organic–inorganic composites with high thermal conductivity, low dielectric constant, and dielectric loss, for applications in the electronic packaging and substrates. Many studies have shown that some polymers filled with high thermal conductivity and low dielectric loss ceramics are suitable for electronic packaging for device encapsulation. Until now, extensive attentions have been paid to the preparation of polymeric composites with high thermal conductivity and low dielectric loss for the application in electronic packaging. In contrast, the thermal conductivities of these dielectric materials are still not high enough and that might restrict their serviceable range. Herein, we briefly reviewed recent progress in this field and introduced a kind of novel composites with surface insulation modified metal aluminum cores to form multilayer coating structures as fillers in polyimide matrix for electronic applications. This structure can significantly improve the thermal conductivity and dielectric properties of composites and give some insights into the effects of modified fillers of composite materials. Such multilayer core–shell structures should have great potentials for the improvement of nanoparticle‐based fillers and applications of electronic packaging. POLYM. COMPOS., 38:803–813, 2017. © 2015 Society of Plastics Engineers     

Deformation mechanisms in polymer fibres and nanocomposites

This review covers the development of the understanding of the deformation micromechanics of both synthetic and natural polymeric fibres using spectroscopic and X-ray diffraction techniques. The concept of fibres as composites, where hard and stiff phases are combined with softer polymeric materials is also discussed. Starting with the first discoveries on the molecular orientation and morphology of polymeric fibres, the widely used concepts of uniform stress and strain are examined for the analysis of fibre deformation. The use of advanced techniques such as Raman and infrared spectroscopies to follow molecular deformation in both rigid-rod (e.g. PpPTA, PBO, PBT, polyethylene) and natural (e.g. cellulose, collagen, silk, chitin) polymer fibres is presented. A clear distinction between fibres that have structures that are subjected to uniform stress or strain is presented, with the evidence that is detected from the response of the molecules (by Raman spectroscopy) and the crystalline fraction (by X-ray diffraction). It is suggested that natural fibres, such as cellulose, silk and others, may have different types of microstructures that are subjected to a uniform strain, which could have potentially led to incorrect determinations of crystal moduli. It is also demonstrated that the Raman and X-ray techniques have been influential on our development of fibres, and have shown that the morphology plays a critical role in mechanical properties. In addition to this, the use of X-ray diffraction using microfocus synchrotron sources is also reviewed. This approach allows a more complete picture of both molecular and crystalline deformations to be developed, and with the advent of nanocomposites it is shown that a combination of the two techniques will be vital for our understanding of their exploitation in technological applications.     

Recent advances in bio‐sourced polymeric carbohydrate/nanotube composites

Nanotubes (NTs), especially carbon nanotubes (CNTs), have attracted much attention in recent years because of their large specific surface area, and their outstanding mechanical, thermal, and electrical properties. In this review we emphasize the development of fascinating properties of polymeric carbohydrate/CNT composites, particularly in terms of their mechanical and conductivity properties and potential applications. Many methods used to modify CNTs during preparation of polymeric carbohydrate/CNT composites are presented. Moreover, we also discuss the enhanced mechanical and electrical effectiveness when hybrid CNTs or halloysite nanotubes were incorporated into different carbohydrate polymer matrices. Finally, we give a future outlook for the development of polymeric carbohydrate/CNT composites as potential alternative materials for various applications including sensors, electroactive paper, electrodes, sorbents for environmental remediation, packaging film, specialty textile, and biomedical devices. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40359.     

碳纳米管/聚合物基导热复合材料研究进展

碳纳米管（CNTs）由于优异的轴向导热性能,是目前制备高热导率聚合物基复合材料的一类重要填料。本文综述了近年来CNTs增强聚合物复合材料的研究进展,探讨了CNTs/聚合物复合材料的导热机理以及CNTs用量、尺寸及结构、表面改性、混杂CNTs粒子和聚合物基体结构等因素对CNTs/聚合物复合材料热导率的影响。同CNTs/聚合物的电导率相比,热导率远低于预期值,归因于CNTs/树脂界面间的声子频率失配现象导致了声子在界面的散射及很高的界面接触热阻,从而降低了体系热导率。分析和总结了改善体系热导率的方法和措施,采用特殊工艺使CNTs在基体内形成特殊的隔离结构或者取向结构是CNTs/聚合物导热复合材料的未来研究及发展方向。     

Graphene as initiator/catalyst in polymerization chemistry

One of the most important applications of graphene-based materials is the formation of nanocomposite materials, where graphene in the bulk-polymer matrix transfers its properties onto the polymeric material. Control of the polymer/graphene interface by attached polymeric interlayers is essential to generate nanocomposites, thus avoiding the aggregation of graphene nanoparticles. Among all graphene materials graphene oxide (GO) and reduced graphene oxide (r-GO) can be prepared on large scales useful for mass production graphene/polymer composites. The direct use of graphene materials as both, the polymerization initiator or catalyst and additive not only diminishes the agglomeration of particles in composites but also reduces the process of composite production to one facile step, which in turn avoids further purification regarding to strong acid initiators and metal particles catalysts. Here, literature activities within the past ∼10 years using graphene-based materials either as initiator or catalyst in different polymerization reactions are reviewed.     

Nanocomposite polymer electrolytes by in situ polymerization of methyl methacrylate: For electrochemical applications

Hybrid materials, which combine properties of organic–inorganic materials, are of profound interest owing to their unexpected synergistically derived properties and are considered as innovative advanced materials promising new applications in many fields such as optics, electronics, ionics and mechanics. Inorganic fillers are added to polymers in order to increase some of the properties of the compounds. These hybrid polymeric materials are replacing the pristine polymers due to their higher strength and stiffness. In the present work, studies concerning the preparation of poly (methylmethacrylate) [PMMA] and the nanocomposites PMMA/SiO₂, PMMA/TiO₂ are reported. These nanocomposite polymers were synthesized by means of free radical polymerization of methylmethacrylate, further “sol–gel” transformation‐based hydrolysis and condensation of corresponding alkoxide was used to prepare the inorganic phase during the polymerization process of MMA. Electrolytes were synthesized based on these nanocomposite polymers and have shown superior properties as compared to conventional polymer electrolytes. The nanocomposites and the nanocomposite polymer electrolytes (NPEs) with different lithium salts were investigated through an array of techniques including FTIR and calorimetry along with the electrochemical and rheological techniques. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of vibrations on interface delamination in metal–polymer composites

The main objective of this work was the study of vibration effects on the viscoelastic coating protecting the steel layer in a metal–polymer composite, with simulated conditions of the transportation of food containers. Mechanical resonance tests in metal–polymer [electrolytic chromium-coated steel–poly(ethylene terephthalate) (PET)] sheets were performed to generate vibration conditions to induce structural modifications in the viscoelastic layer covering the surface of the plates. Consequently, schematic representations of the areas affected by these modifications were made. The modified structures were later analyzed by electron microscopy to detect and evaluate alterations in the morphology of the material. In addition, vibrational Raman spectroscopy analyses were performed to assess the chemical and structural changes on the protective PET at the metal–polymer interface level. The results of this study are expected to provide basic information on the mechanisms and nature of the delamination processes taking place in metal–polymer laminates employed in food-container applications. These damages have previously been detected in some food containers made of PET materials. The study of these damages can lead to the improvement of current composites or the development of higher quality materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012