ONCE A celluloid object has been fabricated, it becomes subject to the chemical, physical, and biological forces of its environment. The visual appearance of deteriorated celluloid varies. Celluloid that has been protected from undesirable environmental conditions will deteriorate according to the mechanisms inherent in its own structure. The cellulose nitrate molecules continue to crystallize around the loci created by the pressures used in manufacture. Camphor molecules are squeezed out, often to the surface where they will sublime at room temperature. This sequence of events leaves celluloid very brittle, cracked, shrunken, warped, collapsed, crumbling, discolored, and crystallized. Celluloid that has been exposed to undesirable environmental conditions is apt to be even more discolored, warped, swollen, softened, mushy, and coated with droplets or a film of nitrate salts and their acids.
The thermal, chemical, photochemical, and physical breakdown of celluloid constitutes a set of highly interrelated decomposition reactions and mechanisms. Light, alkalis, acids, and certain metallic oxides can be very detrimental. The primary environmental contributor to celluloid degradation, however, appears to be moisture. Water is required for most of the aforementioned reactions. Water also has the potential to create physical stresses due to the isotropic nature of celluloid and its capacity for water absorption. Worden discusses a close relationship between nitrate content and absorption of water by cellulose nitrate (, 2:974). As the nitrate content drops (i.e., in degradation) cellulose nitrate can absorb moisture from the atmosphere, increasing the rate of many water-dependent reactions (also see , 158–59) (, 36). This characteristic indicates that celluloid plastics may be more sensitive to moisture than are other more highly nitrated cellulose nitrate materials.
The details are here in the synthesis with a nitrate salt..
It was believed that the amorphous and crystalline regions of the cellulose fibers reacted differentially to the nitration mix. The comparatively large sulfate molecules were believed to enter the amorphous regions, creating pathways for the smaller nitrate groups. The sulfate groups were supposedly too large to enter the crystalline regions, where the nitrate groups had to fend for themselves. This model would indicate that NO3 and SO4 concentrations or percentages would vary randomly throughout a fiber and might explain nonstoicheometric nitration.
Description Homemade nitrocellulose
It offers an important benefit over natural sea salt by allowing greater control over water quality and helping to combat unwanted bacteria, nitrate, phosphate and other unwanted metal
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It is sometimes used in medicine as a diuretic.), sodium nitrate (used in making potassium nitrate, fertilizers, and explosives.), silver nitrate (used in the preparation of silver salts for photography, in chemical analysis, in silver plating, in inks and hair dyes, and to silver mirrors.), and ammonium nitrate (Major uses are in fertilizers and explosives).
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Plus resultant mixture is notonly nitric and sulphuric acids, but also includes potassium or sodium sulphate, whichwill have a negative effect on the quality of the final product.
Complete nitration takes about 10 minutes at room temperature.