Plant-based fibres

Abstract This chapter deals with the structure, properties and applications of natural fibres. Extraction methods of Natural Fibres from different sources have been discussed in detail. Natural fibres have the special advantage of high specific strength and sustainability, which make them ideal candidates for reinforcement in various polymeric matrices. Natural fibres find application in various fields like construction, automobile industry and also in soil conservation. It is the main source of cellulose, an eminent representative of nanomaterial. Extractions of cellulose from plant-based fibres are discussed in detail. Various mediods used for characterization of cellulose nanofibres and advantages of these nanofibres have also been dealt with. 

Mitsubishi said that it plans to substitute plant-based resins and quick-growing plant fibres for materials such as petroleum-based resins and wood hardboards used in car interiors, for environmental reasons. 

Technical barriers would also need to be overcome. All silks are protein-based fibres. Mulberry plants do not fix nitrogen, making the process dependent on external fertilization. It is open to question whether lower levels of fertilization can be employed without compromising the quality of cocoons (Kumar and Kumar, 2011). 

The two main sources of natural fibres are plants and animals. The main component of animal based fibres is various proteins examples include mohair, wool, silk, alpaca, angora, etc. The components of plant fibres are cellulose microfibrils dispersed in an amorphous matrix of lignin and hemi-cellulose examples include cotton, jute, flax, ramie, sisal, hemp, etc. 

Green Modifications of Plant-Based Natural Fibres. 158... 

Hemicellulose is the other major constituent of plant-based namral fibres and it is made up of a combination of 5- and 6-ring carbon polysaccharides [22], It is a branched polymer and has much shorter polymer chains (degree of polymerisation of between 50 and 300) compared to native cellulose. In addition to this, hemicellulose is very hydrophilic in nature [35], easily hydrolysed by acids and soluble in alkali. The role of hemicellulose in natural fibres is to form the supporting matrix for cellulose microfibrils. 

M.M. Kabir, H. Wang, K.T. Lau and E Cardona, Chemical treatments on plant-based natural fibre reinforced polymer composites An overview. Compos. B 43, 2883-2892 (2012). 

A classic example of the creation of macrostructure from molecular organization is cellulose-based fibre materials. Cellulose is the dominant polysaccharide in plant cell walls and is often touted as being the most abundant biopolymer on earth. A basic cellulose unit, known as the elementary fibril, contains thirty-six l,4-(3-D-linked polyanhydroglucopyranose chains (Figure 12.3a), and may eventually be coated with non-cellulosic polysaccharides to form the cell wall microfibril. These microfibrils are then crosslinked by hemicelluloses/pectin matrixes during cell growth. The cellulose molecule is constrained to adopt... 

Fibres can be combined with traditional resins or newer plant based resins. The result is a plant-based alternative for many traditional steel and fibreglass products. Green composites have specific advantages over traditional composites like reduced weight, increased flexibility and greater mouldability. They are also less expensive. These composites have sound insulation capability and are sustainable. In this chapter, we discuss the preparation, structure and... 

The number of published LCAs for biopolymers and natural fibres is quite limited. This seems to be in contrast to the general public interest for this issue and to the more recent interest by policy makers. For example, no comprehensive LCAs have been published so far for PLA (plant-based), cellulose polymers (plant-based), and some fossil fuel-based biodegradable polymers, such as BASF s product Ecoflex. 

Epoxide resins reinforced with carbon and Aramid fibres have been used in small boats, where it is claimed that products of equal stiffness and more useable space may be produced with a 40% saving in weight over traditional polyester/ glass fibre composites. Aramid fibre-reinforced epoxide resins have been developed in the United States to replace steel helmets for military purposes. Printed circuit board bases also provide a substantial outlet for epoxide resins. One recent survey indicates that over one-quarter of epoxide resin production in Western Europe is used for this application. The laminates also find some use in chermical engineering plant and in tooling. 

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