Cotton chemical composition

When exposed to heat, cotton fabrics, like most substances, increase in temperature to an extent that is proportional to their specific heats. Altering the chemical composition of the fabrics such that large amounts of heat are absorbed and released in repeatable cycles of controllable temperature ranges produces fabrics that are described as temperature adaptable. The process insolubili2es poly(ethylene glycol)s cross-linked with methylolamides in the cotton fabric (78). As with flame-retardant cellulose, attachment is through an ether linkage to the cellulose at a relatively low DS. 

Climatic conditions, age, and the digestion process influence not only the structure of fibers but also the chemical composition. Mean values of components of plant fibers are shown in Table 4. With the exception of cotton, the components of natural fibers are cellulose, hemi-cellu-lose, lignin, pectin, waxes, and water-soluble substances. 

Cooke, T.F. "Chemical Composition of Cotton Dust and Its Relation to Byssinosis A Review of the Literature" Textile Research Institute Princeton, New Jersey, 1978. 

Normally, cotton is not dyeable after it has been cross-linked with A-methylolamide agents, such as DMDHEU. This is because the fibers are cross-linked in a collapsed state at elevated temperatures and they cannot swell adequately in aqueous solution to accommodate the relatively large dye molecules. However, cross-linked cotton is dyeable with anionic dyes under acidic pH conditions if reactive alkanolamines or hydroxyalkyl quaternary ammonium salts are incorporated in the finishing formulation. In addition, cotton cross linked with polycarboxylic acid, such as BTCA, or citric acid, is dyeable in similar fashion by using the same methods. Thus, these cross-linked cottons have affinity for acid, direct, and reactive anionic dyes at the pH range of 2.5-6.5, depending on the exact chemical composition of the substrate [561-564]. 

STANSOFT 2597 can be applied to practically all textile fibers and imparts a soft, smooth, slide and full hand. This product is stable with most auxiliaries normally used in the textile industry. STANSOFT 2597 may be applied by exhaustion from a long bath, padding on a solution from a short bath, or by spraying on the surface of wet goods. Due to the special chemical composition of STANSOFT 2597, the product will impart excellent softening effects to polyester/cotton blends and polyester. 

Although jute is a natural fibre like cotton, it differs in chemical composition. Unlike cotton jute contains a high percentage of non-cellulosic matter (about 40%) and the pre-treatment processes of jute are somewhat different from that of cotton. Scouring of jute with caustic soda under pressure cannot be carried out like cotton because of removal of hemi-cellulose which results in high losses of tensile strength (10-15%) and weight (6-8%). 

Interest in the manufacture of different forms of rayon has resulted in the production of regular rayon, hollow viscose, spun-dyed filaments and staple rayon, crimped rayon and surface modified fibers, high tenacity rayon and high wet modulus (polynosic) rayon fibers. In chemical composition, viscose rayon and cotton are alike they are both cellulose. 

In Fig. 15, it is seen that the sheet made of cotton linters is more conductive than the other sheets. The sheet made with "Seagull W" hardwood pulp is the least conductive while the three other pulps have intermediate conductivity values. This behaviour seems to be related to the size of the different types of fibers used to make the sheets. As mentioned previously, hardwood fibers are shorter than softwood fibers, and consequently, there are more interfiber contacts in the sheets made of hardwood fiber. The surface area of a contact is very important to the conductivity. There may be a constrictive effect due to smaller surface at these contacts which results in a restricted flow of ions through the paper, and therefore a lower conductivity. Cotton linters are chemically different and longer than wood fibers and the sheet made of these fibers is more conductive. The difference between the three softwood pulps is probably related to a different chemical composition of its fibers. 

Natural fibers can be classified as seed fibers (such as cotton), bast fibers (like flax, hemp, jute, kenaf, ramie), hard fibers (like sisal), fi-uit fibers (like coir), and wood fibers. The chemical composition and dimensions of some common agro-fibers are presented in Table 5.21. The origin of wood fibers can be sawmill chips, sawdust, wood flour or powder, cutter shavings, pulp or wood residues. As binders for these fibers, both thermosetting (like phenolic, epoxy, polyester) resins and thermosetting matrices [such as polyethylene (LDPE, HDPE), polypropylene (PP), poly(vinyl chloride) (PVC), polystyrene (PS)j can be used. Thermoplastic composites are, however, less expensive to process than thermosetting composites, in addition to their ability to be manufactured into complex shapes. 

The fully developed cotton fibre consists of a waxy cuticle that envelopes it, a cell wall that is differentiated into primary (outer) and secondary (inner) layers and residual protoplasm called the lumen. Although this concept of the fibre structure persists, more recent ideas do not differentiate between the cuticle and the primary wall, which is less than half a micrometer thick and consists of around 50% cellulose, with pectin, waxes and proteins making up the remainder. The secondary wall, which differs considerably in chemical composition and structure from the primary wall, consists of up to 95% cellulose. ... 

Py-GC can therefore be used as an effective means of determining the chemical composition of man-made homopolymer and copolymer fibers, natural fibers, fiber blends, or partly degraded fibers. Pyrograms of polyester, acrylic, and cotton fibers show how these fibers can readily be identified (Figure 8.11). 

Food industries are looking for alternative fats to cocoa butter (CB) from natural matrices that are denoted as cocoa butter replacers (CBRs), cocoa butter equivalents (CBEs) and cocoa butter substitutes (CBSs) fat [41 83], CBRs are defined as non-lauric fats that could replace cocoa butter either partially or completely in the chocolate or other food products. On the other hand, a cocoa butter equivalent (CBE) is a type of fat that has a very similar chemical composition, but its triglycerides derive from other source than cocoa beans, such as palm kernel oil, palm oil, mango seed fat, kokum butter, sal fat, shea butter, illipe butter, soya oil, rape seed oil, cotton oil, ground nut oil and coconut oil [43]. 

In chemical composition, jute is different from linen and cotton. It is composed of a modified form of cellulose called lignocellulose (bastose). 

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