The Chemistry of Powder and Explosives - Sciencemadness Dot Org

NITROCELLULOSE 257
The two substances differ in the configuration of the number 1
carbon atom. In cellulose this atom has the /^-configuration;
2000 or 3000 anhydroglucose units are linked together in long,
straight, threadlike masses which are essentially one dimensional.
In starch the number 1 carbon atom has the a-configuration
which leads to spiral arrangements essentially three dimensional,
and the molecule contains not more than 25 or 30 anhydroglucose
units.
Cellulose contains 3 hydroxyl groups per anhydroglucose unit,
and yields a trinitrate on complete nitration (14.14% N). An
absolutely complete nitration is difficult to secure, but a product
containing 13.75% nitrogen may be produced commercially. If
the conditions of nitration, concentration of acid, temperature,
and duration of the reaction, are less severe, less nitrogen is introduced,
and products ranging all the way from a few per cent of
nitrogen upward, and differing widely in solubilities and viscosities,
may be secured. In the cellulose nitrates which contain less
than enough nitrogen to correspond to the trinitrate, the nitrate
groups are believed to be distributed at random among the three
possible positions, and no definite structural formulas can be
assigned to the materials. Nor is it to be supposed that a sample
which may correspond in empirical composition to cellulose mononitrate
or dinitrate really represents a single chemical individual.
Collodion is a nitrocellulose which is soluble in ether-alcohol
and contains, according to the use for which it is destined, from
8%, more or less, of nitrogen to 12% or thereabouts. The name of
pyroxylin is now generally applied to collodion of low nitrogen
content intended for use in pharmacy, in the making of lacquers
or of photographic film, or intended in general for industrial uses
outside of the explosives industry. In 1847 Maynard discovered
that nitrocellulose existed which was soluble in a mixture of ether
and alcohol although it would not dissolve in either of these
solvents taken singly. 92 The discovery soon led to the invention
of collodion photography by Archer in 1851. Chardonnet's first
patent 93 for artificial silk was granted in 1884. Celluloid, made
by dissolving collodion nitrocellulose in camphor with the use of
92 After the material is dissolved, the solution may be diluted either
with alcohol or v.-*th ether without precipitating.
93 French Pat. 165,345 (1884).