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Biofillers based on cellulose, chitin, starch, and their composites have been topics of interest during the last few decades because of their eco-friendliness, low-cost, and good thermomechanical properties. The biofillers based on plant fibers are hydrophilic that reduce the compatibility with rubber matrix. In this manuscript, an effort has been made to review cellulose, chitin, and starch, focusing on their preparation and properties of natural rubber (NR) based composites reinforced with these fillers. The main characterization properties of NR based composites, such as mechanical, thermal, and biodegradability were discussed. The filler-NR interactions were also explored. The small size of the filler improved the physical interaction between the filler and matrix, and consequently, mechanical, thermal, sorption, crystallinity, and biodegradability of the biofillers/NR composites were found to be improved. Finally, the applications of NR-based composites reinforced with cellulose, chitin, and starch were reviewed in different areas such as medical, food packaging, footwear, sensors and water purification to study their practical uses.

This study aims to extract cellulose nanofibers (CNFs) from a sustainable source, i.e. millet husk, which is an agro-waste worthy of consideration. Pre-treatments such as mercerisation, steam explosion, and peroxide bleaching (chlorine-free) were applied for the removal of non-cellulosic components. The bleached millet husk pulp was subjected to acid hydrolysis (5% oxalic acid) followed by homogenization to extract CNFs. The extracted CNFs were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Dynamic Light Scattering (DLS), Energy Dispersive X-ray Spectroscopy (EDX), Thermogravimetry (TG and DTG), Differential scanning calorimetry (DSC), and Solid state

In this work, graphene was used as a filler for banyan aerial root fibers reinforced epoxy composites at various compositions. The synergetic effect of graphene and banyan fibers, on the physical a...

Background: This era has seen outstanding achievements in materials science through the advances in natural fiber-based composites. The new environmentally friendly and sustainability concerns have imposed the chemists, biologists, researchers, engineers, and scientists to discover the engineering and structural applications of natural fiber reinforced composites. Objective: To present a comprehensive evaluation of information from 2000 to 2018 in United States patents in the field of natural fibers and their composite materials. Methods: The patent data have been taken from the external links of US patents such as IFI CLAIMS Patent Services, USPTO, USPTO Assignment, Espacenet, Global Dossier, and Discuss. Results: The present world scenario demands the usage of natural fibers from agricultural and forest byproducts as a reinforcement material for fiber reinforced composites. Natural fibers can be easily extracted from plants and animals. Recently natural fiber in nanoscale is preferred over micro and macro scale fibers due to its superior thermo-mechanical properties. However, the choice of macro, micro, and nanofibers depends on their applications. Conclusion: This document presents a comprehensive evaluation of information from 2000 to 2018 in United States patents in the field of natural fibers and their composite materials.

We report the synthesis of giant carbon particles with spherical and interconnected porous morphologies. Direct organic–organic self-assembly between phenolic resin and polystyrene-block-poly(ethylene oxide) (PS-b-PEO) was employed to prepare these highly ordered carbon particles. Mesoporous carbon nanoparticles with tunable textural characteristics such as large surface area, uniform pore structure, and high thermal properties were achieved by simply adjusting the ratio between the block copolymer to phenol without using acid, base, or activating agents. The synthesized nanoparticles possess a very high surface area of up to 832 m2 g–1, and ultrasmall pore size, as small as 3 nm, and exhibited excellent electrochemical performance when used as active electrodes for lithium-ion batteries. Making use of the secondary interactions between the functional groups of the block copolymer and phenol, this study created tunable nanoparticles with excellent surface area and uniform morphologies that can be used in ...

Designing environmentally friendly materials from natural resources represents a great challenge in the last decade. However, the lack of fundamental knowledge in the processing of the raw materials to fabricate the composites structure is still a major challenge for potential applications. Natural fibers extracted from plants are receiving more attention from researchers, scientists and academics due to their use in polymer composites and also their environmentally friendly nature and sustainability. The natural fiber features depend on the preparation and processing of the fibers. Natural plant fibers are extracted either by mechanical retting, dew retting and/or water retting processes. The natural fibers characteristics could be improved by suitable chemicals and surface treatments. This survey proposes a detailed review of the different types of retting processes, chemical and surface treatments and characterization techniques for natural fibers. We summarize major findings from the literature and the treatment effects on the properties of the natural fibers are being highlighted.

In this work, we have developed super tough ternary polymer blends and composites composed of polystyrene (PS), low-density polyethylene (LDPE), polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) and exfoliated graphene nanoplatelets (xGnP). A 50/50 composition of PS and LDPE was selected for making the binary blend. The addition of xGnP in the binary blend reduces the tensile strength, elongation at break and tensile toughness considerably due to the unfavorable interactions existing between PS, LDPE, and xGnP. On the other hand, the mechanical properties of PS/LDPE binary blends are considerably improved by the addition of SEBS at the expense of modulus. The best results were obtained for a 33/33/33 (PS/LDPE/SEBS) composition. Further, different concentrations of xGnP were incorporated in the ternary blend with 33/33/33 composition. Interestingly, the composites show a significant improvement in mechanical properties especially for 2.91 wt% xGnP modified ternary blend. The DMA studies revealed that the stress with in the ternary composites are minimum when compared with binary blends and their composites. The variation in the phase morphology of the binary blends by the addition of SEBS and xGnP is responsible for the dramatic changes in mechanical and viscoelastic properties. This study validates large improvement in mechanical properties of the PS/LDPE polymer blends by the careful selection of SEBS and xGnP. Keywords: Polystyrene, Low-density polyethylene, Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene, Exfoliated graphene nanoplatelets, Toughened plastics

The aim of this study is to investigate natural cellulosic fibers extracted from Tridax procumbens plants. The obtained fibers were alkali treated for their effective usage as reinforcement in composites. The physical, chemical, crystallinity, thermal, wettability and surface characteristics were analyzed for raw, and alkali treated Tridax procumbens fibers (TPFs). The test results conclude that there was an increase in cellulose content with a reduction in hemicellulose, lignin, and wax upon alkali treatment. This enhanced the thermal stability, tensile strength, crystallinity, and surface roughness characteristics. The contact angle was also lesser for treated TPFs which prove its better wettability with the liquid phase. The Weibull distribution analysis was adopted for the analysis of the fiber diameter and tensile properties. Thus the considerable improvement in the properties of alkali treated TPFs would be worth for developing high-performance polymer composites.

Bio adsorbents have received tremendous attention due to their eco-friendly, cheap and non-toxic nature. Recently, bio-adsorbent-based membranes have been frequently employed for water treatment. The work reports the preparation of a novel adsorbent membrane from hierarchical zeolite, polyvinyl alcohol, carboxymethyl cellulose and agar. The fabricated membrane was characterized spectroscopically and microscopically with several techniques such as XRD, UTM, TGA, optical microscopy and FT-IR, as well as contact-angle studies. The result showed that the hierarchical-zeolite-loaded membrane is superior in terms of thermal stability, mechanical properties and surface roughness. The fabricated membrane was investigated for its efficiency in the removal of Congo red dye in aqueous conditions. The influence of pH, temperature, contact period and the initial concentration of dye and zeolite loading on the adsorption process are also explored. The adsorption results highlighted the maximum sorption property of Congo red on agar/zeolite/carboxymethyl cellulose/polymer biomembrane was found to be higher (15.30 mg/g) than that of zeolite powder (6.4 mg/g). The adsorption isotherms and kinetic parameters were investigated via Langmuir, Freundlich and pseudo-first order, pseudo-second order and the intraparticle diffusion model, respectively. The adsorption isotherms fitted well for both considered isotherms, whereas pseudo-second order fitted well for kinetics. The thermodynamic parameter, ΔG at 303 K, 313 K and 323 K was −9.12, −3.16 and −0.49 KJ/mol, respectively. The work further explores the antibacterial efficacy of the prepared membrane and its reusability.

In this work, fillers of waste chicken feather and abundantly available lignocellulose Ceiba Pentandra bark fibers were used as reinforcement with Biopoxy matrix to produce the sustainable composites. The aim of this work was to evaluate the mechanical, thermal, dimensional stability, and morphological performance of waste chicken feather fiber/Ceiba Pentandra bark fiber filler as potential reinforcement in carbon fabric-layered bioepoxy hybrid composites intended for engineering applications. These composites were prepared by a simple, low cost and user-friendly fabrication methods. The mechanical (tensile, flexural, impact, hardness), dimensional stability, thermal stability, and morphological properties of composites were characterized. The Ceiba Pentandra bark fiber filler-reinforced carbon fabric-layered bioepoxy hybrid composites display better mechanical performance compared to chicken feather fiber/Ceiba Pentandra bark fiber reinforced carbon fabrics layered bioepoxy hybrid composites. The Scanning electron micrographs indicated that the composites exhibited good adhesion at the interface of the reinforcement material and matrix system. The thermogravimetric studies revealed that the composites possess multiple degradation steps, however, they are stable up to 300 °C. The thermos-mechanical studies showed good dimensional stability of the composites. Both studied composites display better thermal and mechanical performance compared to neat bioepoxy or non-bioepoxy thermosets and are suitable for semi-structural applications.

In the present work, we have developed a mesoporous silicalite-1 using CMC as a template for the removal of MB from aqueous solution. The synthesized silicalite-1 were characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDX) and N2 adsorption-desorption isotherm (BET). XRD and FTIR analysis confirmed the formation of crystallinity and development of MFI structure in the mesoporous silicalite-1. The adsorption of MB dye on mesoporous silicalite-1 was conducted by batch adsorption method. The effect of various parameters such as adsorbent dosage, initial dye concentration, contact time and temperature on the dye uptake ability of silicalite-1 was investigated. The operating parameters for the maximum adsorption are silicalite-1 dosage (0.1 wt%), contact time (240 min), initial dye concentration (10 ppm) and temperature (30℃). The MB dye removal onto mesoporous silicalite-1 followed pseudo-second-order kinetic and Freundlich isotherm. The silicalite-1 exhibits 86% removal efficiency even after six adsorption-desorption cycle. Therefore, the developed mesoporous silicalite-1 is an effective eco-friendly adsorbent for MB dye removal from aqueous environment.

In the present work, we modified ZSM-5 zeolite using a bio polymer poly (diallyl dimethyl ammonium chloride) and employed it for the removal of cationic dye, methylene blue from aqueous solution. The chemical and physical properties of the modified ZSM-5 zeolite were investigated using XRD, FTIR, SEM, TEM, nitrogen adsorption, TGA and 27Al NMR. Modified ZSM-5 zeolite possesses high surface area and pore diameter which was confirmed from SEM, TEM and nitrogen adsorption analysis. Adsorption of methylene blue on zeolite was investigated by batch adsorption technique. The effect of different parameters such as zeolite dosage, initial methylene blue concentration, temperature, pH and contact time on the adsorption process was discussed. Maximum adsorption capacity (4.31 mg/g) was achieved using 0.1g of modified ZSM-5 zeolite at the optimum conditions (initial dye concentration: 10 mg/L, pH: 10, temperature:30oC and contact time: 300 min). The experimental data were fitted into Langmuir and Freundlich models and the results indicate that the adsorption process followed Freundlich isotherm. Kinetic data were investigated using pseudo-first-order and pseudo-second-order models. Kinetic analysis indicates that pseudo-second-order model is more suitable to describe adsorption of MB on modified ZSM-5 zeolite. The reusability test suggests that the adsorbent could be reused at least six times without significant loss in removal efficiency.

A cheap and eco-friendly polyvinyl alcohol (PVA)/chitosan (CS)/honey membrane was successfully developed using solvent casting technique. The prepared membranes were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), contact angle, optical microscopy (OM) and universal testing machine (UTM) analysis. XRD results indicate that the membrane is crystalline, while FT-IR data confirm the successful incorporation of honey into the PVA/chitosan membrane. SEM analysis revealed that the surface morphology of the PVA/CS membrane is intact even after the incorporation of honey, which is corroborated by AFM and optical microscopic analysis. Contact angle measurement suggests that the hydrophilicity of the membrane increases with honey concentration. The membrane possesses good thermal and mechanical stability as indicated by TGA and UTM analysis. Disc diffusion method was employed to investigate the antibacterial activity of the membrane and the result shows that the membrane possesses good antibacterial activity against Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria). The antibacterial activity of the membrane could be tuned by honey concentration and 15 wt% honey loaded membrane displayed highest zone of inhibition (diameter: 8 mm (E. coli) and 14 mm (S. aureus). Our studies thus suggest that the PVA/chitosan/honey membrane could be a potential candidate for wound dressing applications.

Biopolymers attract many researchers due to their remarkable properties; hence they are exploited in several fields. The present chapter covers the effect of metal oxide nanoparticles on mechanical, thermal, antibacterial, and barrier properties of biopolymers. The properties of metal oxide-filled biocomposites are depended on the load transferability between polymer and filler. Therefore, it is necessary to understand the key mechanisms of the interactions in the polymer composites such as filler and polymer and filler-filler interaction because it helps to widen their range of applications. Hence, this chapter covers the recent development in biopolymers containing metal oxides such as copper oxide, zinc oxide, and magnesium oxide.

Polymers play a vital role in many applications such as bearings, gears, sealings, bushes, pulleys, artificial hip replacements, etc. The study of the wear behavior of such polymers leads to a better understanding of the performance of these materials in different conditions such as dry sliding, high temperature, and lubrication. Progress in polymer tribology provides a variety of applications of polymer-based industries. There are several reports that describe new materials that can enhance the wear performance of these polymeric materials. In particular, the reinforcement with fibers and fillers of such materials allows withstanding much harsher environmental conditions. The concerns toward nonbiodegradable materials have led to the need for environmentally friendly materials. Therefore, bio-based polymers reinforced with natural fibers are nowadays used, for example as an alternative brake friction material to replace asbestos. Thus, the natural fiber-reinforced polymer composites paved the way for the new developments in the field of tribological applications. This chapter discusses the tribological applications of polymer and polymer composites.

Alginate is a naturally occurring biopolymer which has been widely used to design materials for wound dressing. The attractive features of alginate include biocompatibility, biodegradability, antibacterial activity, hydrophilicity, and nontoxicity. Alginate accelerates wound healing by providing a moist environment around the wound, removing wound exudate, and restricting the colonization of microorganism. The properties such as mechanical, water adsorption, biodegradability, and cell affinity of the alginate are generally improved by incorporating it with polymers and nanoparticles. The alginate has often been encapsulated with several drugs to enhance its wound healing properties. In this review, we discussed about the recent literature about several types of alginate-based nanocomposite for wound healing application. This chapter gives an overview of the recent developments of alginate-based materials in wound dressing, which outlines the characteristic properties of different alginate-based wound dressing materials.

It is a major challenge to reduce water diffusion through hydrophilic polymers like epoxies without affecting their thermomechanical performance. Herein, both graphene oxide (GO) nanosheets and barium oxide (BaO) microparticles were incorporated together into epoxy to develop water resistant epoxy/BaO/GO nanocomposite. The manuscript signifies the role of these fillers in reducing water diffusion through epoxy matrix without deterioration in its basic thermal and mechanical properties. Morphological studies of epoxy/BaO/GO nanocomposites revealed the presence of uniformly distributed micro/nano-clusters of graphene oxide sheets and BaO. This enhanced the hydrophobicity of the nanocomposite with a water contact angle of 131.7°. The BaO/GO micro/nano-clusters also created a barrier to the diffusion of water molecules which reflected in the lower diffusion coefficient of epoxy/BaO/GO nanocomposite. Dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and thermomechanical (TMA) analysis has been carried out to investigate the viscoelastic, thermal stability, and dimensional stability of the prepared composites. Good viscoelastic performance of epoxy/BaO/GO nanocomposite with balanced thermal stability and dimensional stability has been confirmed. The developed water resistant epoxy nanocomposite is suitable to be used in areas where moisture attack is a serious concern.

Chitosan is a natural biopolymer with immense applications due to the biodegradable, nontoxic, antimicrobial, and other biological properties. Due to the functional groups, they are combined with various nanofillers and others for various biomedical applications. Although chitosan has anticancerous activity, the combined effect of chitosan and nanofillers in the form of bionanocomposites makes them more advantageous over the conventional treatments of cancer. Chitosan-based nanocomposites are investigated for tumor imaging, drug delivery, photodynamic therapy, and inducing apoptosis and/or necrosis in cancerous cells. Hence, this chapter will discuss the role of chitosan in cancer, nanotechnological innovations, and various chitosan-based nanocomposites in the field of cancer.

The present work aims to study the free vibration and damping properties of pure bamboo bioepoxy composites (B), pure basalt bioepoxy composites (b), and bamboo/basalt fiber reinforced hybrid bioepoxy composites. The pure and hybrid composites were fabricated by hand layup technique with different layering sequences such as BBBB, bbbb, BbBb, BBbb, BbbB, and bBBb. Experimental modal analysis was performed to obtain the natural frequency and the damping characteristics of the fiber reinforced composites. Variations in the natural frequency and damping characteristics were noticed with different layering sequences of the fiber in the composites. For instance, a higher natural frequency was obtained when bamboo fiber was stacked on the top surface and an enhanced damping behavior was noticed when basalt fibers were used as skin layer in hybrid composites. Numerical analysis was performed and the results were compared with the experimental results.

Phenolic resins are brittle at room temperature, hence to obtain suitable properties such as enhanced mechanical, thermal, etc., the phenolic resins are preferred to incorporate with fiber and/or filler. The phenolic based composites could be used to make complex geometries as they possess high strength and stiffness with high impact properties; hence, they would be the best alternative for metals. Furthermore, phenolic resins are well resistant to burning. It produces lesser smoke and toxic fumes, so they could be utilized in construction and building materials where high-temperature resistance is required. Therefore, numerous methods have been used to enhance the fire, mechanical, physical, etc., properties of phenolic resins by incorporating different sizes of fillers and/or fibers. However, the dispersion of nanoclay in the polymer matrix can limit the efficiency of composites. This chapter highlights the recent research works done on mechanical properties, X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and tribological properties of nanoclay based phenolic matrix composites. Also, it explored how these properties were managed.

Active food packaging films, which involve the use of nanoparticles in food packaging applications, have gained significant attention from researchers in recent years. This chapter focuses on various properties of chitosan-based hybrid nanocomposite films incorporated with one or more nanofillers and their suitability for food packaging applications. The influence of filler type and filler concentration on the material properties such as tensile, thermal, crystalline, water barrier, and antibacterial activity of the chitosan-based nanocomposites have been discussed. The mechanism behind the improvement in properties and the changes in material behavior due to the incorporation of nanofillers has also been highlighted.

Food packaging is essential for storage, handling, transport, and preservation of food, keeping food wastage and loss at a minimum level. Various materials such as plastic, glass, wood, metal, plant parts, etc. are being used as food packaging, with plastic dominating the field. However, most of the food packages developed today are disposed of after their first use. This raises concerns about the environmental impact of the packaging. Various strategies such as recycling, reducing, and reusing of packaging have the potential to decrease this impact. There is a rising demand for the development of effective and efficient sustainable packaging, which is safe for health and the environment. This chapter discusses the different food packaging materials and the environmental impacts of food packaging and the waste management methods along with the regulations for the packaging materials.

Here the fabrication of a novel PVA/CMC/halloysite nanoclay membrane for the effective adsorption of cationic dye (methylene blue, MB) from aqueous environment is reported. The membranes were analyzed through scanning electron microscopy (SEM), optical microscopy (OM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), contact angle and universal testing machine (UTM) analysis. The adsorption behavior of the membrane in terms of nanoclay loading, contact time, initial concentration of MB, pH and temperature were also discussed. The membrane exhibits excellent removal efficiency (99.5%) for MB in the optimal conditions such as nanoclay dose = 6 wt%, initial dye concentration = 10 ppm, contact time = 240 min, pH = 10 and temperature = 30 °C. Three isotherm models (Freundlich, Langmuir and Temkin) were employed to analyze the dye adsorption data. The results revealed that the adsorption process could be described well with both Freundlich and Langmuir isotherm model. The kinetics of MB adsorption onto membrane follows pseudo-second-order model while thermodynamic parameter indicate that adsorption is feasible and endothermic in nature. The antibacterial studies revealed that the PVA/CMC/halloysite nanoclay membrane possess notable antibacterial property. Finally, the desorption studies showed that the membrane have good reusability even after four recycles.

In a world that canopies numerous opportunities to advance towards a green sustainable life, biopolymer development offers a platform that fits into the paradigm of achieving an eco-friendly environment whilst reducing reliance on the scarce fossil fuel elements for the fabrication of day-to-day products. Today's technological improvements have aided biopolymer end-products to escalate to higher purposes and soon may have their performance level in par with the petroleum-based synthetic polymers. The motive of this paper is to shimmer light on some aspects of biopolymers that include its classes, properties, composites and applications. Depending on the type of class on the basis of various categories, many enthralling chemistries of polymer composition can be substantiated. Essential properties can imparted to the ensuing biopolymer by altering its chemical configuration and method of synthesis while also focusing on its functional purpose. Nowadays, biopolymer composites blend qualities of one biopolymer with another to acquire an enhanced component that showcases unique explicit attributes. There are several techniques to process biopolymer composites, of which in-situ, infiltration and electrospinning methods have captured considerable limelight. Biopolymers and its composites have embarked captivating impressions in regions of biomedical, packaging, agricultural and automotive applications. Although their efficacy is yet to reach their fossil fuel counterparts, biopolymers have laid a distinguishing mark that will continue to inspire creation of novel substances for many years to come.