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Whole arrowroot powder, soy protein isolate and red cabbage anthocyanin were used to fabricate packaging films that can monitor the freshness of shrimp and can be used to detect ammonia.

Sensor films are finding wide range of applications. Different type of sensing films is fabricated for the identification of chemicals, ions, heavy metals, changes in the pH, etc. The present report is on the fabrication of pH sensitive films from completely natural sources-soy protein isolate, chitin nano whiskers and flower extract. The highly crystalline chitin nano whiskers (CNW) were extracted from prawn shell under neutral condition via steam explosion technique. Multifunctional Soy protein isolate (SPI) films were prepared by adding chitin nanowhisker and

Recycled polymers and biopolymers are receiving a great deal of attention these days. If these two can be combined, it will lead to an environment-friendly green material with a great deal of applications. Here the present work is about incorporating bio-based fillers in a recycled polyurethane matrix. Two unusual and extremely novel sources of cellulose have been proposed. The celluloses obtained from Cissus latifolia and Ficus benghalensis were selected as sources. These sources have not been utilized and reported elsewhere to date. The cellulose modified samples of recycled polyurethane were analyzed using FTIR, scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) to have a preliminary idea about the combination. We found that these were successful as fillers in the matrix. The percentage of crystallinity was decreased in both the composites, which indicates the miscibility. Comparing the two sources, Cissus latifolia based cellulose was more effective in producing interesting morphologies and they had a percentage crystallinity of 75%, which was very high compared to all the reported works.

Polyurethanes (PUs) are one of the most widely used polymers in research and industry. They can be synthesized from chemical sources and natural sources. PUs are a very useful class of polymers and exhibit many desirable properties that can be exploited in various applications. PUs are formed by the reaction between polyols and isocyanates. A wide variety of polyols and isocyanates are available for synthesis, and hence we can produce a large number of PUs. PUs show high mechanical strength, chemical resistance, flexibility, and resilience. One of the major advantages of some specially designed PUs is their ability to recover their primary shape, which is known as shape memory. The shape-memory effect (SME) of PUs makes them popular in biomedical, electronic, and thermal applications. The SME can be monitored using different measures such as shape fixity, recovery time, and recovery rate. Various stimuli are applied to shape-memory materials to induce shape memory. PU polymers can be modified with different nanofillers, and these fillers influence the shape-recovery parameters. PU composites are popular because of a good property–price relationship. This chapter discusses the various factors affecting the SME of PU composites and the effect of different types of fillers on the PU matrix.

The increased applications of Polyurethane (PU) materials give rise to a higher amount of wastes, which have a devastating effect on the earth in turn; therefore, the management of end-of-life wastes is one of the most important issues in the modern world. Although incineration and landfilling are the most common procedure adopted for waste disposal, but both of them caused environmental problems such as air and soil pollution. Moreover, the former triggers global warming, and the latter causes water pollution making the problem worst. As a consequence, finding economical and environmentally friendly methods are a high priority topic for researchers to overcome this problem. Fortunately, recycling is an environmentally attractive solution, and there is an increased interest by the researchers in recycling PU wastes. Several recycling techniques for PUs have been described in the technical and scientific literature. Without any doubt, glycolysis reaction is one of the most important recycling method, especially for rigid and flexible PUs. In this review, glycolysis of waste polyurethane foam (PUF) materials with different glycols and catalysts, especially metallic ones were considered, and the effect of some additional parameters such as the nature of glycol, catalyst, temperature and material ratio were discussed too. In addition, a brief description on characterization of recycled products, and potential application of regenerated products is carried out.

Hydrogels have been a familiar term in the current biomedical research. Generally, hydrogels are swollen polymer networks with water. Biocompatibility and ease of preparation are the key properties which enable them to be used in a variety of biomedical applications. Hydrogels can be classified in a number of ways depending on a wide range of properties. The chapter discusses in detail about the general properties, classification, mechanical properties, and biocompatibility of hydrogels. The special emphasis is on the biocompatibility. The factors affecting the elasticity and mechanical strength will be discussed along with the characterization techniques.

Robots and robotics are two familiar terms in the current era. The development of robotics was a milestone in technology and research. Artificial intelligence is key for the development of robotics. Nowadays, new inventions in robots and their applications are a hot topic. Polymers are an unavoidable part of robotics. The components of robots require a lightweight as well as durability and flexibility and, hence, polymers play an inevitable role. Thermoplastics, acrylates, urethanes, nanomaterials, etc., are being widely selected in robotics. Electroactive and conducting polymers are widely used classes of materials in robotics. The ionic and shape memory polymers also have an important place in robotics. Robots that are used to mimic living beings are an important part and are common in biological applications. They require flexible materials like polymers. This chapter provides a systematic analysis of different types of polymers used in the robotics field.

Polymer mixing is one of the direct and practical strategies for creating new superior materials for commercial and industrial applications. The polymer blend can reinforce the setting of the properties according to the focused need. The compatibility of the immiscible polymer mixing system by incorporating a new material, helps in the development of high-performance materials. In general, graft, block or random copolymers have widespread applications as compatibilizers. Compatibilization is based on a specific chemical reaction between two functional polymer components during mixing, and is known as a reactive mixing. The introduction of reactive and functional polymers into an immiscible polymer blend with a strong interaction between the two polymer components of the mixtures can improve the adhesion between the components. Functional polymers have significant importance because of the high compatibilizing efficiency since the compatibilizer is created directly between the interfaces. In this chapter the interfacial reaction and morphology, the effect of reactive polymers on the polymer mixing process, the relationship between the flow field or process parameters, the compatibilizing efficiency of a reactive compatibilizer in different mixing techniques will be discussed. The concept of reactive compatibilizer, the characterization techniques used to monitor the compatibility of functional polymers, future perspectives and challenges in this field will also be discussed in this chapter.

In the present paper, we have carefully investigated the morphology and fracture mechanism of the recycled polyurethane (RPU)/epoxy blend system. The second phase (RPU) added to the epoxy resin has a positive effect on the overall mechanical properties. Interestingly, the recycled polymer has a remarkable effect on the fracture toughness of epoxy resin. The mechanism behind the fracture toughness improvement up on the addition of RPU was found to be very similar to that of the incorporation of hyperbranched polymers in epoxy resin. Brittle to ductile fracture was clear in the case of higher loadings such as 20 and 40 phr of RPU in the epoxy resin. The mechanism behind improvement of fracture toughness was found to fibrillation of the RPU phase which was evidenced by the fracture morphology. In fact the force applied to the epoxy matrix was effectively transferred to the added RPU phase due to its strong interaction with the epoxy phase. This effective transfer of force to the RPU phase protects the epoxy matrix without catastrophic failure and we observed 44% increase in G1C values at an addition of 40 phr RPU. This results in the extensive fibrillation of RPU which causes the generation of new surfaces. Thus the impact energy has been fully utilized by the RPU phase. The mechanism is termed as simultaneous reinforcing and toughening and normally reported as a result of cavitations and yielding. SEM, HRTEM and AFM analyses clearly demonstrated the fibrillated morphology of the fracture surface and the formation of nanostructures. This report is first of its kind in the case of both epoxy modification and the elastomer toughening.

Smart materials are much discussed in the current research scenario. The shape memory effect is one of the most fascinating occurrences in smart materials, both in terms of the phenomenon and its applications. Many metal alloys and polymers exhibit the shape memory effect (SME). Shape memory properties of elastomers, such as rubbers, polyurethanes, and other elastomers, are discussed in depth in this paper. The theory, factors impacting, and key uses of SME elastomers are all covered in this article. SME has been observed in a variety of elastomers and composites. Shape fixity and recovery rate are normally analysed through thermomechanical cycle studies to understand the effectiveness of SMEs. Polymer properties such as chain length, and the inclusion of fillers, such as clays, nanoparticles, and second phase polymers, will have a direct influence on the shape memory effect. The article discusses these aspects in a simple and concise manner.

A novel and cost-effective approach towards the modification of epoxy matrix has been developed using recycled polyurethane for the first time without sacrificing any of the intrinsic properties of the resin. Polyurethane, recycled from waste foam by glycolysis process (RPU), was found to be very effective in improving the properties of the thermosetting resin based on Diglycidyl ether of bisphenol-A (DGEBA). The effect of the addition of polyurethane on the mechanical and viscoelastic properties was analyzed and the morphological changes with the inclusion of varying concentrations of RPU were examined by High Resolution Transmission Electron Microscopy (HRTEM). All the blends remained transparent, even after curing by a reaction induced phase separation process (RIPS) of the epoxy phase and hence suggests the development of microphase separation and nanostructure formation. The nanoscale morphology is very clear even with 15 phr concentration of the recycled polyurethane. The morphology at high concentration (40 phr) of RPU under HRTEM showed very distinct ordered interpenetrating network (IPN) like formation and a phase in phase morphology. The size of the dispersed RPU particles varied from 32 to 80 nm as the concentration of RPU varied from 15 to 40 phr in the epoxy phase. This is the first report where nanoscale morphology development by viscoelastic phase separation (VPS) process. The tensile strength values varied from 57 MPa for neat epoxy to 68 MPa for the 40 phr blend. The fracture toughness was increased by 83% for the addition of 40 phr RPU. The recycled PU can be considered as excellent low cost reinforcing filler for epoxy resin where strength and modulus of epoxy resin could be improved simultaneously with an increase of fracture toughness.

Green synthesis of nanoparticles is a widely explored field of research. Many types of biogenic materials have been proposed and employed to synthesize nanoparticles of different metals. Unexploited sources are still there in the nature which can produce wonderful results. The present manuscript is examining two of such sources-the Crape Jasmine (CJ) and Dwarf White Bauhinia(DWB) flowers. Both of these white colored flowers effectively reduced copper salt to CuO nanoparticles and the catalytic action was enhanced by the addition of Averrhoa bilimbi extract. The results suggest that the different species of plants having same colour produced same effect on the reduction process. By the combined action of fruit and flowers’ extract we could reduce the particle size to many smaller values. This manuscript presents and effective method to produce nanoparticles of extremely smaller size by green synthesis. From the Fourier transform infrared spectra and UV–Visible spectra, the formation of CuO nanoparticles were confirmed and the DLS analysis presented a reduction in the particle size to less than 20 ​nm.

Nanotechnology is a demanding field of research where new inventions and technologies are emerging. Synthesis, characterization, and application are the common routes of study in nanomaterial research. To apply synthesized or derived nanomaterials like nanoparticles, nanocomposites, nanodevices, etc., they must first be characterized to gain an in-depth understanding of the properties and factors influencing their behavior. Nanomaterial characterization is a wide, complex field of study because a large number of nanomaterials and characterization techniques are available. An understanding of the morphology, spectra, thermal, and mechanical properties are always required to properly apply materials. Mechanical properties of nanomaterials are crucial in applications like electronic devices, sensors, composites, etc. Nanocomposites find a variety of applications in industry as well as in research, where mechanical strength is an unavoidably necessary property. The present chapter extensively deals with mechanical property analysis of different nanomaterials. The chapter discusses the properties of nanoparticles of inorganic and organic origin, network-structured materials, materials derived from nanoparticles, and materials having nanodimensions.

The chapter gives an introduction to the polyurethane (PU) polymer, its synthesis and its structure. The chapter details the different methods of polyurethane synthesis, various starting materials and the necessary components required for PU synthesis. The chapter also deals with the phase separation process of polyurethane and the effect of phase separation on the morphology, thermal, and mechanical properties of PU. The application of spectral techniques such as FTIR and NMR in the structural determination of polyurethane are also covered.