Fibres natural polymeric

Natural polymeric fibres have (literally) supported the development of human civilisation since its prehistoric beginnings. A particularly prominent role has been played by cellulose, a polysaccharide which is one of the world s most abundant and versatile fibrous polymers. Cellulose fibres are the reinforcing component of wood, a natural composite that can be fashioned into devices used for shelter, transportation, agriculture, war, communication, ornament and recreation. Cellulose fibres have been woven into clothing, twisted into ropes and bowstrings, and processed into papyrus and paper. Fibrous proteins, especially keratin (wool, mohair), collagen (hide, parchment, catgut) and silk also have a rich history and an assured future as useful materials. 

Natural polymeric fibres, mostly cellulosics, have been used since ancient times for reinforcement. Mechanical properties of these are inferior to glass, carbon or aramid fibres. Cellulosics are usually used as a laminating material, in the woven form. Processing... 

In addition to plastics materials, many fibres, surface coatings and rubbers are also basically high polymers, whilst in nature itself there is an abundance of polymeric material. Proteins, cellulose, starch, lignin and natural rubber are high polymers. The detailed structures of these materials are complex and highly sophisticated in comparison the synthetic polymers produced by man are crude in the quality of their molecular architecture. 

Three factors affect the essential nature of a polymeric material and determine whether it is glassy, rubbery, or fibre-forming under a given set of conditions. These are ... 

From the earliest times man depended upon nature for polymeric materials like wood as fuel, furs and fibres as clothing, grain and flesh as food. Many polymeric materials behave as plastics, i.e., in some stage of their fabrication they are soft and putty like and can be moulded into any desired shape and then set to retain that shape. 

Organic polymers are manufactured and used on a massive scale as plastics and elastomers, films and fibres in areas as diverse as clothing, car tyres, compact discs, packaging materials, prostheses and most recently electroluminescent and electronic devices and sensors. The enormous growth in the use of organic polymeric materials since the 1930s can be mainly attributed to their ease of preparation, lightweight nature and unique ease of fabrication. 

In nature, thread-like polymeric material fulfils an essential structural role. Plant life is built mainly from cellulose fibres. Animal life is built from linear protein material such as collagen in skin, sinew and bone, myosin in muscle and keratin in nails and hair. The coiled polypeptide chains of the so-called globular proteins which circulate in the body fluids are folded up to give corpuscular particles. 

The best known products of macromolecular chemistry are plastics, synthetic rubber and fibres. The world average per capita consumption of plastics exceeded 8 kg (44 kg in the USA and in Japan). The production of synthetic fibres and rubber exceeds the production of the natural materials. A large proportion of these substances is produced by polymerization. 

---