Nitrocellulose varnishes

Introduction. Today nitrocellulose is one of most important derivatives of cellulose used in industry and commerce, and a major product of the chemical industry. Its wide and manifold applications are due mainly to its extraordinary physical properties. Thus a protective coating of nitrocellulose varnish, a nitrocellulose film or a tube of smokeless powder — all are characterized by relatively high elasticity and mechanical strength. These properties are a direct consequence of the microstructure of cellulose, which is composed of highly oriented long-chain molecules of polysaccharide. Not only nitrocellulose, but also other derivatives of cellulose, such as other esters and ethers, demonstrate similar characteristics. 

Esters and ethers of cellulose, and especially nitrocellulose, are most widely used in the form of a colloidal solution. This technique is applied in the manufacture of smokeless powder, nitrocellulose varnishes, film and celluloid. 

Ford Model T with nitrocellulose varnish finish... 

The salt was used for electric igniters. The substance was mixed with nitrocellulose varnish and fixed on the resistance bridge. 

Use (Mixture, usually also containing normal amyl chloride). Solvent (nitrocellulose, varnishes, lacquers, neoprene), rotogravure inks, soil fumigation, organic compounds. 

Methyl ethyl ketone is essentially intended for solvent uses, in direct or indirect form, chiefly in paints and resins, nitrocellulose varnishes, adhesives and inks, and also for lubricant dewaxing. Its average commercial specifications are listed in Table lOtlO. 

OTHER COMMENTS used as a pharmaceutical aid used as a synthetic flavoring substance useful in the manufacture of smokeless powder, photographic films, artificial leather, artificial silk, and perfumes applications as a solvent for nitrocellulose, varnishes, lacquers, and aeroplane dopes. 

In practice, esters from adipic, sebacic, and phthalic acid are frequently used as polyester plasticizers. The value of n may vary from 3 to 40 for adipates and from 3 to 35 for sebacates. Polyester plasticizers are seldom used alone. They are used in combination with monomeric plasticizers to reduce the volatility of the mixed solvents. They offer a higher resistance to plasticizer migration and to extract by kerosene, oils, water, and surfactants. Polyester plasticizers are used specially in PVC-based blends and in nitrocellulose varnishes. 

Solvent products. These products contain solvents of various mixtures, types and concentrations depending on the properties desired (e.g., application mefliod, surface film or skin formation, see above 18.3.1,18.3.2.1, Table 18.3.1 and 18.3.2). Solvents are normally the main components of these products (for example up to 80 % in nitrocellulose varnishes, low solids). 

Polyepoxide plasticizers are specially used for PVC, for chlorinated rubber, and in nitrocellulose varnishes. Ethylene-vinyl acetate copolymers (EVA) (vinyl acetate content of 65-70% by weight) are also of industrial interest as high-molecular-weight plasticizers for PVC, mainly because of their low cost [46]. A polymeric plasticizer commercially available from du Pont (PB-3041) allows the... 

Absence of condensation when breathing on film indicates film is unvarnished. To test for commonly applied nitrocellulose varnish, apply several drops of a mixture of one part diphenyl and 100 parts concentrated sulfuric acid to film surface. Appearance of blue colour indicates presence of varnish. Polymer varnishes are readily identified by the Beilstein test for halogens... 

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