A.H. Bhat

Natural fiber reinforced poly(vinyl chloride) composites : a review.

Materials from renewable resources – also called biomaterials or ‘green’ materials – are presently gaining in importance worldwide. In these times of continuous increases in the price of crude oil and discussion of carbon dioxide (CO2) emissions, conventional plastics have reached a price level and a questionable image which promotes the search of alternatives. Natural fibers are a renewable natural resource and are biodegradable, which is an important characteristic for components that must be disposed of at the end of their useful life. They are recyclable and can be easily converted into thermal energy through combustion without leaving residue. In this study, we will discuss the natural fiber reinforced polyvinyl chloride composites, reinforcing effect, plasticization effect along with modification by coupling agents, properties, and applications based on composite materials. Also, the polyvinyl chloride-based composite materials with specific emphasis on effect of coupling agent, foamed polyvinyl chloride composites, and the effect of natural fiber reinforcement on its material properties will be reviewed. One of the best alternatives is natural fiber reinforced plastics composites. These are composites that are typically filled or reinforced with plant fibers, as well as plastics such as polyvinyl chloride or recently, even bioplastics.

Empty Fruit Bunches as a Reinforcement in Laminated Bio-composites

In this article, we study laminated bio-composites that were reinforced with empty fruit bunches. Five-ply veneer laminated bio-composites were prepared by alternately arranging oil palm trunk veneer and empty fruit bunch mat. Composites were made with a gluing layer of 250 or 450 g/m2 of phenol formaldehyde. The mechanical, physical, and thermal (TGA) properties of the composite were studied. Results indicated an improvement in mechanical, physical, and thermal properties of the laminated bio-composites with the use of empty fruit bunches as reinforcement. The water absorption and thickness swelling of laminated bio-composites that were reinforced with empty fruit bunches were better than bio-composites not reinforced with empty fruit bunches. Laminated bio-composites with the use of empty fruit bunch as reinforcement showed better bending strength, bending modulus, and screw withdrawal. Thermal stability for laminated bio-composites with empty fruit bunch also improved. Images taken with a scanning electron micrograph indicated an improvement in the fiber-matrix bonding for the laminated panel glued with 450 g/m 2 of phenol formaldehyde.

Polymer blend of PLA/PHBV based bionanocomposites reinforced with nanocrystalline cellulose for potential application as packaging material

The current research discusses the development of poly (lactic acid) (PLA) and poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced nanocrystalline cellulose bionanocomposites. The nanocrystalline cellulose was derived from waste oil palm empty fruit bunch fiber by acid hydrolysis process. The resulting nanocrystalline cellulose suspension was then surface functionalized by TEMPO-mediated oxidation and solvent exchange process. Furthermore, the PLA/PHBV/nanocrystalline cellulose bionanocomposites were produced by solvent casting method. The effect of the addition of nanocrystalline cellulose on structural, morphology, mechanical and barrier properties of bionanocomposites was investigated. The results revealed that the developed bionanocomposites showed improved mechanical properties and decrease in oxygen permeability rate. Therefore, the developed bio-based composite incorporated with an optimal composition of nanocrystalline cellulose exhibits properties as compared to the polymer blend.

Cellulosic Nanocomposites from Natural Fibers for Medical Applications: A Review

The nanocellulose and its composites have been covered in this chapter which is confirmed to be a very versatile material having the wide range of medical applications, including cardiovascular implants, scaffolds for tissue engineering, repair of articular cartilage, vascular grafts, urethral catheters, mammary prostheses, penile prostheses, adhesion barriers, and artificial skin. These implants were produced from bioresorbable and/or biodegradable materials. Nanocellulose, such as that produced other than microfibrillated cellulose and cellulose nanowhiskers, is also produced by the bacteria (bacterial cellulose, BC) which is also an emerging biomaterial with great potential as a biological implant, wound and burn dressing material, and scaffolds for tissue regeneration. Moreover, the nanostructure and morphological similarities with collagen make cellulose attractive for cell immobilization and cell support. This article describes current and future applications of cellulosic nanofibers in the biomedical field. Cellulose micro-/nanofibril as a reinforcing material for composites is becoming more and more attractive to researchers in composite science because of its potential lightweight and high strength. In the present article, we have reviewed the nanocellulosic fibers-based nanocomposites for medical applications. Processing methods, properties, and various applications of cellulosic composites are also discussed in this article. However, the separation of cellulose nanofibers along with the manufacture of cellulose nanocomposites is still challengeable. The aim of this chapter is to demonstrate the current state of development in the field of cellulose nanofibril-based nanocomposite research and application through examples.The nanocellulose and its composites have been covered in this chapter which is confirmed to be a very versatile material having the wide range of medical applications, including cardiovascular implants, scaffolds for tissue engineering, repair of articular cartilage, vascular grafts, urethral catheters, mammary prostheses, penile prostheses, adhesion barriers, and artificial skin. These implants were produced from bioresorbable and/or biodegradable materials.

Development and Material Properties of Chitosan and Phosphomolybdic Acid-based Composites

This work reports the development and characterization of chitosan/ phosphomolybdic acid-based composite membranes. The prepared composite membranes were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), tensile strength test, and thermogravimetric analysis (TGA). FTIR spectroscopy indicated the proper molecular interactions between chitosan and PMA. XRD spectroscopy indicated the semi crystalline nature of the composite membranes. DSC study showed the presence of single glass transition temperature (Tg) at 156°C in the 20% PMA-doped membrane, which indicates the miscible nature of chitosan and PMA blend. TGA study indicates increase in thermal stability of the composite membranes as compared to pure chitosan. Mechanical properties of the composite membranes were found to be enhanced significantly.

IMPACT PROPERTIES OF NATURAL FIBER HYBRID REINFORCED EPOXY COMPOSITES

The hybrid composites were fabricated by taking cheaply available empty fruit bunch fibers and jute fibers trilayers as reinforcement in epoxy matrix using simple hand lay-up-technique. Thermal, mechanical and morphological properties were characterized. The notched izod impact strength of most hybrids increased with respect to the virgin matrix. The laminates coupled with 2-Hydoxy ethyl acrylate (HEA) showed better impact properties than the one without coupling agent. The addition of fibers and coupling agent considerably improved the thermal stability (i.e., decomposition and residue content) of the hybrids. The thermal properties measured by thermogravimetric analysis (TGA) showed that fibres and coupling agents improved thermal properties. The impact fractured composite specimens were analyzed using field emission scanning electron microscopy (FESEM) to know the morphological behaviour.

Electrospun Cellulose Composite Nanofibers

This chapter deals with the structure, properties, and applications of electrospun-based cellulose composites. Extraction methods of cellulosic nanofibers from different sources are discussed in detail. Cellulose has the special advantage of high specific strength and sustainability, which make them ideal candidates for reinforcement in various polymeric matrices. Cellulose nanofibers find application in various fields, including construction, the automobile industry, and soil conservation. Cellulose, an eminent representative of nanomaterial obtained from various natural fibers, can be dissolved in various solvent systems, which are described in detail in this study. Thermoplastic-based electrospun cellulose nanocomposites and their applications are highlighted. This chapter describes current and future applications of electrospun cellulosic nanofibers in various fields.

Extraction of Lignin from Biomass for Biodiesel Production

The renewable biorefinery concept involves transforming a pulp mill into a multipurpose biofuels, biomaterials, and biopower production facility in which these products are produced in an ecofriendly and sustainable manner. A key challenge in this process is the recovery of lignin from process streams such that it can be utilized in a variety of innovative green chemistry processes. This chapter focuses on the various methods used for the recovery of lignin and application of lignin. The study also discusses about the production of biofuel, specifically biodiesel via Lignoboost lignin pyrolysis as biofuel, steam gasification/pyrolysis of kraft lignin for biofuel, lignin hydrocracking for biofuel and hydrogenation of black liquor. Besides this, the study also throws some light on the availability of biomass, its sources, and global production of biodiesel.

CHAPTER 16:Micro and Nano Calcium Carbonate Filled Natural Rubber Composites and Nanocomposites

Rubbers in general are seldom used in their pristine form. They are too weak to fulfill practical requirements because of lack of hardness, strength properties and wear resistance. So they are used with a number of other components called fillers which improve the processability, performance properties and life of the final product. Calcium carbonate has been mainly used as filler to reduce the cost of rubber products. With the development of technology in superfine filler production and especially in surface modification, calcium carbonate used as reinforcing filler has caught great attention. As inert inorganic filler, nano calcium carbonate has not exhibited the similar reinforcing effect as traditional reinforcing fillers such as carbon black till now. In this chapter, we will discuss the distribution of rubber around the globe, and the development of elastomeric composites with the incorporation of micro and nanocalcium carbonate as a filler material. Also, this chapter will cover the effect of various filler parameters on the material properties of composites with special focus on natural rubber, Acrylonitrile butadiene rubber and Styrene butadiene rubber based composites. These findings may be useful as a guideline for the development of rubber materials for various engineering purposes with required performance.

Improvement of the Red Mud Polymer-Matrix Composites by Organophillization of Red Mud

Red mud was organophilized by aniline formaldehyde and to know the effect of various filler loading on the properties of PVA-Organophilized red mud composite prepared by a conventional solvent casting technique and comparison of the same with that of the virgin polymer, various characterizations was done. The as-synthesized composite films were typically characterized by FTIR spectroscopy and X-Ray Diffraction.The exfoliation of galleries of organo- red mud was more evident in the composite film containing 2% of filler loading.The morphological image of the composite materials was studied by scanning electron microscopy (SEM) and optical microscope (OM). The thermal properties measured by thermogravimetric analysis (TGA) showed that organored mud enhanced the thermal stability of a series of composite materials freestanding films.The differential scanning calorimetry (DSC) showed increase in glass transition temperature and crystallization of the composite films.