Diffusion Foundations Vol. 23

Abstract: The current chapter focus on the transport phenomenon of polymeric composites . the factors like nature of polymer, temperature, fillers and nature of crosslink can affect the transport properties of a composite. Transport phenomenon in different type of polymer is also studied in the paper.

Abstract: In early composite materials, the use of petroleum based fibers such as glass and carbon fibers, aramid etc. was common. In order to reduce the dependency on petroleum based sources and environmental pollution, researchers have focused on the search for alternative sources. Natural fibers are abundant, recyclable and biodegradable plant derived materials. Besides, thanks to good physical, thermal and mechanical properties, natural fibers become promising alternative for composites. This review includes information about natural fiber reinforced composites’ components, manufacturing methods, mechanical properties and applications.

Abstract: Ceramic composites is playing crucial role to accomplish highly efficiently and cost effective equipment for aerospace industry. The instigation of ceramics into aircraft industry is a promising step towards virtuous future. Ceramics has a key role in innovation of highly competent material for space travel which is highly economical and environmentally sustainable. Advancement in making fuel efficient engines are necessity in present scenario due to the harmful emissions releases in the environment by burning of fuel to power up engine. The high temperature application of composites makes it very attractive for aerospace applications. This light weight material has potential to thrust spacecraft upto ten times quicker with the identical fuel consumption, therefore significantly depreciating size of vehicle and increasing travel distance. The implementation of ceramics into jet engines and turbines increase the efficiency of engine due to its lighter weight and better thermal capabilities. A jet engine employing ceramic composites has manifest 15% more fuel saving when compared to the simple nickel based alloys. Hence, ceramic composites can replace nickel based alloys which has been a promising candidate for the engines of commercial aircrafts. Some disadvantages has been also discussed that is brittle failure and limited thermal and shock resistance.

Abstract: In this chapter, bamboo fiber with parallel and anti parallel orientation has been introduced in the Unsaturated polyester (UPE)/ Epoxidized Soybean Oil Acrylate (ESOA) blend. The reinforced fiber mats were treated with NaOH and NaOH-silane to improve the stiffness and strength of the composites. Parallelly oriented fiber reinforced composite showed improved glass transition temperature. The mechanical, thermal, storage modulus and tribological properties are highly improved for parallel fiber oriented composite. Also alkali-silane treated fiber reinforced composite show optimum properties than alkali treated and raw fiber based composites. Anti parallelly oriented composites show reduced performance due to pull out of fibers. The FTIR analysis of all the composites was observed for the first time with valid reaction mechanism. So this new partially biodegradable composite can open a new door for potential application in various fields. This composite may be used as an alternating material to wood for various indoor and outdoor applications.

Abstract: This chapter reviews recent development of graphene-based polymer composites. The formation of graphene oxide and graphene are a vital two dimensional (2D) material has received a lot of research interest in commercialization aspect due to its excellent electrical, thermal as well as mechanical properties at very low filler content. In this manner, utilization of graphene-based polymer composites with different polymer matrixes have been attracted increasing attention in recent years for both fundamental studies and applied research into industrial applications in many fields. Herein, novel properties of polymer (epoxy, polystyrene, and PANI) / graphene composites will be reviewed along with detailed examples drawn from the scientific literature. Keywords: Graphene-based polymer composites, thermo-mechanical properties, two dimensional (2D) materials

Abstract: Electroactive polymers, or EAPs, are polymers that show an adjustment fit as a fiddle when invigorated by an electric field. Ionic polymer metal composites (IPMCs) are electro-dynamic polymers with great electromechanical coupling properties. They are proficient applicants in many progressed innovative applications, for example, actuators, artificial muscles, biomimetic sensors, and so forth. Type of membrane and electrodes determines the morphology and structure of IPMCs. IPMCs can be prepared using physical loading, chemical deposition and electroplating methods. The assembling of anodes for IPMCs is exceptionally basic in their electromechanical coupling. Optimization of force, determination of cations and molecule size dispersal inside the IPMC structure, and so on are the different components, which decides their proficiency. An ionic polymer-metal composite (IPMC) comprising of a thin Nafion sheet, platinum plated on the two side faces, experiences extensive twisting movement when an electric field is connected over its thickness. Then again, a voltage is created over its appearances when it is all of a sudden bends. IPMCs are best known for their proving advantages such as biocompactible, low activating voltage and more power efficiency

Abstract: The discovery of carbon nanotubes is one of the remarkable achievement in the field of material science and it is a great advancement of Nanotechnology. A carbon nanotube is an expedient material used in several domains and paves way for the welfare of humans in many ways. Carbon nanotubes are nanosized tubes made from graphitic carbons and it is well known for its exclusive physical and chemical properties. The market demand for the nanotubes has increased progressively due to its size dependent, structure and mechanical properties. The carbon nanotubes possess high tensile strength and it is also found to be the durable fibre ever known. It is also found to possess exceptional electrical properties. The carbon nanotube composites have an excellent young’s modulus and higher tensile strength same as graphite carbon. This review plots the properties of carbon nanotubes and portrays the planning and properties of carbon nanotube composites. The wide application of carbon nanotube composites is also explained.

Abstract: Polymer electrolyte membranes (PEM) with good properties are essential for the improvement of electrochemical operations. The increase in properties of polymer electrolyte membranes will develop the performance of polymer electrolyte membranes in the fuel cells. The importance of polymer electrolyte membranes is increasing recently due to its activity and simplicity in energy associated applications like automobiles and various portable applications. PEM has various properties like proton conductivity, chemical stability, mechanical properties, thermal stability and so on. These properties are enhanced and influenced by various factors like morphology, the molecular weight of the membranes, chemical structures, cross linkages etc. The present chapter attempts to summarize about the properties of polymer electrolyte membrane involved in the different types of electrochemical utilizations. Keywords: Polymer electrolyte membrane, fuel cells, morphology, proton conductivity, chemical structure.

Abstract: The possibility of creating polymeric nanocomposites with desired properties can be achieved by mixing it with an appropriate nanomaterial. The carbon-based nanomaterials have an excellent combination of both physical and chemical properties which create a significant interest among the researchers to prepare an industrially useful material employing carbon based nanomaterials as the filler. The thermo-mechanical properties of materials are studied to characterize their internal state and structure. In this chapter, the thermomechanical properties of polymer-CNT nanocomposites and the various factors affecting the thermomechanical properties are discussed.