Synthetic fibres biopolymer

Concerning the cleaning of industrial sewage, both national and international standards are high. A nonwoven of reclaimed fibres is good value and functional, and can substitute for costly synthetic fibre materials. The nonwoven can be used to adsorb heavy metal ions (Pb(+2) ions, Cu(+2) ions, Zn(+2) ions), acid dyes (C.l. acid red 27, C.l. acid red 88) and oils (basic oil SN 150, diesel, crude oil). This requires a particular kind of surface modification treatment. For example, the woollen nonwoven is treated with biopolymer chitosan and low temperature plasma to ensure that heavy metals are better adsorbed. Investigations have shown that woollen reclaimed fibres are especially well suited to adsorb Pb (+2) ions. The adsorption of copper and zinc is also clearly improved through chitosan and plasma treatment. 

Shanmugasundaram, O. L. (July/September 2007). Biopolymers in healthcare medical applications. Synthetic Fibres, 13—17. 

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. 

In recent years starch, the polysaccharide of cereals, legumes and tubers, has acquired relevance as a biodegradable polymer and is becoming increasingly important as an industrial material (Fritz Aichholzer, 1995). Starch is a thermoplastic polymer and it can therefore be extruded or injection moulded (Balta Calleja et al, 1999). It can also be processed by application of pressure and heat. Starch has been used successfully as a matrix in composites of natural fibres (flax, jute, etc.). The use of starch in these composites could be of value in applications such as automobile interiors. An advantage of this biopolymer is that its preparation as well as its destruction do not act negatively upon the environment. A further advantage of starch is its low price as compared with conventional synthetic thermoplastics (PE, PP). 

Ideally, thus the key design principles in natural polymers fibres can be elucidated and compared to man-made polymers. Such comparison would offer the potential for the design of greatly improved synthetic biopolymers. 

General use of analytical pyrolysis is given in Table 2.23. The earliest application of analytical pyrolysis was the identification of the isoprene unit in rubber in 1860 [565]. Analytical pyrolysis is now extensively applied for the analysis of natural and synthetic polymers, textile fibres, wood products, foods, leather, paints, varnishes, adhesives, paper, biopolymers (proteins, polysaccharides), etc., and allows the study of a broad variety of materials including carpets, clothing, electronic components, upholstery, plastic recyclates, fuel sources, oil paintings, etc. 

A wide range of polymers from solution, sol-gel suspension, or melt can be electrospun into nanofibres. To date, over 200 types of various materials including natural polymers, synthetic polymers and hybrid blends have been used to obtain electrospun fibres [36]. Due to the practicality, mouldability, flexibility, lightness, durability and chemical and physicochemical stability, natural polymers are more preferable to synthetic polymers. Therefore, four major classes of biopolymers including proteins, polysaccharides, deoxyribonucleic acids (DNAs) and lipids as well as their derivatives have been fabricated into electrospun scaffolds [37, 38], The most popular natural polymers include chitosan, collagen, gelatin, casein, hyaluronic acids, silk protein, chitin and fibrinogen [37-43]. 

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