Synthetic polymer fibres

The third main class of separation methods, the use of micro-porous and non-porous membranes as semi-permeable barriers (see Figure 2c) is rapidly gaining popularity in industrial separation processes for application to difficult and highly selective separations. Membranes are usually fabricated from natural fibres, synthetic polymers, ceramics or metals, but they may also consist of liquid films. Solid membranes are fabricated into flat sheets, tubes, hollow fibres or spiral-wound sheets. For the micro-porous membranes, separation is effected by differing rates of diffusion through the pores, while for non-porous membranes, separation occurs because of differences in both the solubility in the membrane and the rate of diffusion through the membrane. Table 2 is a compilation of the more common industrial separation operations based on the use of a barrier. A more comprehensive table is given by Seader and Henley.1... 

Cotton Carbon fibre Steel wire Glas fibre Synthetic polymer ... 

W. Beckmann, in D. M. Nunn, ed.. The Dyeing of Synthetic Polymer and Acetate Fibres, Dyers Company PubHcations Tmst, London, 1979, Chapt. 5. 

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. 

HILL. R. (Ed), Fibres from Synthetic Polymers, Elsevier, London (1953)... 

The reinforcing filler usually takes the form of fibres but particles (for example glass spheres) are also used. A wide range of amorphous and crystalline materials can be used as reinforcing fibres. These include glass, carbon, boron, and silica. In recent years, fibres have been produced from synthetic polymers-for example, Kevlar fibres (from aromatic polyamides) and PET fibres. The stress-strain behaviour of some typical fibres is shown in Fig. 3.2. 

This cost will depend on the nature of the product. For liquids collected at the site in the customer s own tankers the cost to the product would be small whereas the cost of packaging and transporting synthetic fibres or polymers to a central distribution warehouse would add significantly to the product cost. 

The dyeing of synthetic-polymer and acetate fibres, Ed. D M Nunn (Bradford SDC, 1979). 

The lower limit 100 for the DP of high polymers has been established because the physical properties needed for useful fibres, elastomers, plastics and coatings, are not characteristic of low Molecular weight polymers. However, there is no upper limit for DP. Thus, the average Molecular weight for most Synthetic polymers is 10,000 to 1,00,000. However, in some cases, Molecular weights of over 100 millions have been found. 

Polymers nowadays are not difficult to prepare because of the easy availability of the raw materials. Most of the Synthetic polymers are of recent origin but they have made an impact on our daily life. They have found extensive applications in textile fibres, rubber and rubber goods, building materials, packaging, fancy decorating articles and ion-exchange resins. 

Synthetic polymers include a variety of products such as plastic, fibres, elastomers, rubber, etc. 

Much of our technology has been developed by observing and imitating the natural world. Synthetic polymers, such as those you just encountered, were developed by imitating natural polymers. For example, the natural polymer cellulose provides most of the structure of plants. Wood, paper, cotton, and flax, are all composed of cellulose fibres. Figure 2.15 shows part of a cellulose polymer. 

A variety of synthetic polymers as plastic (polythene), synthetic fibres (nylon 6,6) and synthetic rubbers (Buna - S) are examples of manmade polymers extensively used in dally life as well as in Industry. 

Synthetic polymers are man-made high molecular mass macromolecules. TTiese include synthetic plastics, fibres and rubbers. The two specific examples are polythene and dacron. 

D.M. Nunn (Ed.), The Dyeing of Synthetic-polymer and Acetate Fibres, Society of Dyers and Colourists, Bradford, 1979. 

Chapter 10 of Fibres from Synthetic Polymers, ed. R. Hill. 

Hill, R. Fibres from synthetic polymers, p. 259. London Elsevier Publishing Co., 1953. 

Related to ionic liquids are substances known as deep eutectic solvents or mixtures. A series of these materials based on choline chloride (HOCH2CH2NMe3Cl) and either zinc chloride or urea have been reported (Abbott et al., 2002 2003). The urea/choline chloride material has many of the advantages of more well-known ionic liquids (e.g. low volatility), but can be sourced from renewable feedstocks, is non-toxic and is readily biodegradable. However, it is not an inert solvent and this has been exploited in the functionalisation of the surface of cellulose fibres in cotton wool (Abbott et al, 2006). Undoubtedly, this could be extended to other cellulose-based materials, biopolymers, synthetic polymers and possibly even small molecules. 

I. Goodman, Synthetic Fibre-forming Polymers , Royal Institute of Chemistry,... 

Bunn CW, Chapter 12 in "Fibres from synthetic Polymers" (Hill R, Ed) Elsevier Sci Publisher, Amsterdam, 1953. Cowie JMG and Toporowski PM, Eur Polym J 4 (1968) 621. 

Bunn CW, "Polymer Texture Orientation of Molecules and Crystals in Polymer Specimens", in Hill R (Ed), "Fibres from Synthetic Polymers", Elsevier, Amsterdam, 1953, Chap. 10. 

Natural polymers include cellulose (the "fibre" in your food) and DNA. Synthetic polymers include plastics, polystyrene (see below), and the material you will produce in this activity. 

A. M. CunUffe and P. T. Williams, Characterisation of products from the recycling of glass fibre reinforced polyester waste by pyrolysis. Fuel, 82, 2223-2230, (2003). J. H. Harker and J. R. Backhurst, Fuel and Energy, Academic Press London, 1981. A. C. Albertson and S. Karlsson, Polyethylene degradation products, In Agricultural and Synthetic Polymers, ACS Symposium Series 433, J. E. Glass and G. Swift (eds), American Chemical Society, Washington DC, 60-64, 1990. 

CW Bnnn. In R Hill, ed. Fibres from Synthetic Polymers, pp 240-300. Amsterdam Elsevier, 1953. 

The microhardness of thermally untreated gelatin of 400 MPa surpasses that of all commonly used synthetic polymers and soft metals and the value for the thermally treated gelatin of almost 700 MPa (Vassileva et al, 1998) approaches that of the carbon-fibre-reinforced composites. 

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