Chitin natural biopolymer

Chitosan Chitosan has a molecular structure similar to cellulose. This material is produced from chitin, which is widely found in the exoskeleton of shellfish and crustaceans. Chitin is the second most abundant natural biopolymer after cellulose. Chitosan is a good adsorbent for all heavy metals. It has been estimated that chitosan can be produced from shellfish and crustaceans at a market price of 15.43 /kg. 

In addition to synthetic biodegradable polymers discussed so far, naturally occurring biopolymers have also been used for fabricating implantable dmg delivery systems. Examples of natural biopolymers are proteins (e.g. albumin, casein, collagen, and gelatin) and polysaccharides (e.g. cellulose derivatives, chitin derivatives, dextran, hyaluronic acids, inulin, and starch). 

We used the crosslinked chitosan fiber (hereafter called ChF) in this experimental study. ChF was fabricated by Fuji Spinning Co., Japan. Fig.l shows the unit molecular structure of chitosan which was transformed from chitin by deacetylation. Chitin is a natural biopolymer which is contained in the shell of arthropods. Chitosan was crosslinked to make an adsorbent with acid, alkaline, and chemical proofs. The fabrication method of ChF was presented elsewhere.[S,6]. 

Chitin is an abundant natural biopolymer and exhibits excellent antimicrobial properties. To obtain enhanced antimicrobial properties, deacetylated products of chitin—chitosan (CS) have to be synthesised, which includes the introduction of alkyl groups to the amine groups to produce quaternised N-alkyl CS derivatives, the introduction of extra quaternary ammonium grafts to CS and modification with phenolic hydroxyl moieties. 

Chitosan is a natural biopolymer that has many desirable characteristics as a scaffold or encapsulation material. It is a biodegradable, semicrystalline polysaccharide obtained by A-deacetylation of chitin, which is harvested from the exoskeleton of marine crustaceans. Chitosan is composed of glucosamine and A-acetyl glucosamine which are linked by glycosidic bonds. Being structurally similar to ECM components, chitosan provides cell-ECM interactions which guide cell behavior. 

Chitin is a naturally abundant mucopolysaccharide and is the second most abundant natural biopolymer after cellulose. Nature produces approximately 10 tons of chitin annually worldwide as a by-product [12], and industrial use has been estimated at 10,000 tons annually. In nature, chitin is present in life forms and more particularly in insects and crustaceans where it represents the major component of their exoskeleton. It is a highly insoluble material resembling cellulose in its solubility and low chemical reactivity (Figure 16.1). Although chitin itself is insoluble in water, on deacetylation, it yields CS, which is soluble under acidic conditions. When the degree of acetylation falls below the value of 60 mol%, chitin becomes CS. 

Chitin is the most abundant natural biopolymer after cellulose. Chitin is a common constituent of exoskeletons of crustaceans and cell walls of fungi and insects (Bartnicki-Garcia 1968), composed of A-acetyl-D-glucosamine residues, as illustrated in Figure 36.1. 

Lifetime estimations are very useful for the development or selection of materials (e.g., polymers) for different applications especially where long-term usage is essential. The lifetime is usually determined by accelerated aging, like air oven aging studies, which require long time periods. Natural biopolymers, for example, chitin, have own lifetimes, which values are very important parameters. The apparent kinetic parameters calculated according to the above-described manner have been used to calculate the value of lifetime of chitin. The lifetime has been defined as the time when the mass loss reaches 5 mass%, i.e., a = 0.05 [75-78] and can be estimated by the following equation, if the mechanism reaction is F (see Table 22.2) ... 

Other natural ingredients identified as allergens in moisturizers are placenta,70 chitin (a celluloselike biopolymer and important structural element of the integuments of arthropods, particularly crustaceans, mollusks, unicellular micro-organisms, seaweed, and fungi), and chitosan (deacetylated chitin).78-79... 

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