Cotton, purified

Purified cotton consists of the fibers of different cultivated varieties of Gossypium sp. The material is freed from adhering impurities, deprived of fatty matter, bleached, and sterilized. The length of cotton fibers is up to about 5 cm, the diameter varies between 9 to 25 pm. A typical cotton fiber is cylindrical when young, but becomes flattened and twisted as it matures. The genuine cellulose wall of the cotton fiber is covered with a waxy cuticule. Delipidation is essential in order to transform the genuine fiber to absorbent cotton wool which is readily wetted by water. 

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The final product was subjected to ferric chloride-hydrochloric acid treatment in the same manner as commercial glucose and starch. A linear carbon dioxide-time relationship was observed which was practically identical with that for starch. In other words purified cotton cellulose, on relatively complete hydrolysis, appeared to give glucose in a... 

A recent modification of the hydrolysis-oxidation technique19 has produced strong support for the acid hydrolysis results already mentioned. In this instance samples of purified cotton linters were treated for varying times with boiling 2.5 N hydrochloric acid or with 2.5 N hydrochloric acid- 0.6 M ferric chloride. The latter was necessary where the hydrolysis extended over periods longer than 12 minutes and acted to hinder the formation of humic materials. By filtration and washing, a series of hydrocelluloses was obtained which corresponded to times of hydrolysis varying from 0 to 7 hours. 

Airway Constrictor Activity of Purified Cotton Bract... 

Fig. 81. Electron micrograph of cellulose fibres, from purified cotton and wood pulp respectively, magnification 39,000, according to RSnby [41a].

The recent systematic investigations carried out by Newman et al. [37] were devoted to the viscosity, sedimentation, diffusion and osmotic pressure of nitro-celluloses prepared by nitrating non-purified cotton, purified cotton, and viscose fibres with mixed add containing phosphoric acid and phosphoric anhydride. 

The chem compn of a typical cotton fibre is as follows Cellulose 86.1, protein 1.2, water 8.3, pectins 1.1, ash 1.1, wax 0.6, sugars 0.3, pigments - trace, others 1.3. Purified cotton is practically pure cellulose, while some cottons which have simply been dried contain as high as 96% cellulose. For chem prop of cellulose, see under Cellulose... 

Cotton, Chemical, The basic raw material from which NC and cellulose acetate are made. Chemical cotton is chemically purified cotton linters (See under). The raw linters contain impurities such as proteins, fats, waxes, pectins, sugars, inorganic salts and mechanically entrapped vegetation, dirt, wood etc, all of which must be removed... 

Specifications for purified cotton linters are covered in US Spec MIL-C-206. The requirements are as follows moisture, max 7% alkali sol mat-... 

Pyrocellulose is made commercially from purified cotton linters or hull shavings or wood cellulose, most commonly by the mechanical dipper process. The thoroughly dry cellulose is introduced into the mixed acid contained in an iron or stainless steel... 

A, purified cotton cellulose B, cellulose (75%)-polyacrylonitrile (25%) copolymer (y-radiation initiated) C, cyanoethylated cellulose (D.S. 0.7) D, cyanoethylated cellulose (D.S. 0.7) (62%)-polyacrylonitrile (38%) copolymer (y-radiation initiated) E, cellulose (75%)-polyacrylonitrile (25%) copolymer (ceric ion initiated). 

A purified cotton B fibrous cellulose-polyacrylonitrile C cyanoethulated cotton... 

Purified cotton linters Tertiary butanol Water... 

Cellulose acetate originally was made from purified cotton Enters, but this raw material has been entirely replaced by wood pulp. The other raw materials used are acetic acid and acetic anhydride. 

Hydrogen sulphide, phosphine PH3, and stibine SbH3, give a similar reaction. They may be removed by means of a purified cotton-wool plug impregnated with copper(I) chloride. 

Purified cotton fibers irradiated in nitrogen at 298 K. Precision of these determinations is low. 

Cellulose acetates. Cellulose acetate is a well-known derivative of cellulose and has found many uses as a fiber. Acetate, diacetate, and triacetate are similar in chemical structure with acetate having about 83 percent of the hydroxyl groups acetylated, and not less than 92 percent hydroxyl groups are acetylated in triacetate. Triacetate and diacetate fibers are manufactured by the acetylation of refined wood pulp or purified cotton linters. The acetylation reaction is chemically quite simple and may be visuahzed in the following manner ... 

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