NITROCELLULOSE

NITROCELLULOSE

CAS NO.:  9004-70-0
EC/LIST NO: 682-719-5

Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid. 
One of Nitrocelluloses first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. 
Nitrocellulose was also used to replace gunpowder as a low-order explosive in mining and other applications.

Nitrocellulose with alcohol appears as a white solid mixed with ethanol or another solvent to form a slurry. 
A mixture of the dinitrates and trinitrate of cellulose.
Exposure to heat may evaporate the solvent leaving a residue that is subject to self-accelerating decomposition and may explode if confined or present in large quantities. 
Treat as an explosive. 
Produces toxic oxides of nitrogen when burned.

Pyroxylin solution appears as a solution in absolute ethanol or another organic solvent of cellulose nitrate (nitrocellulose) that contains 11.5-12.3% nitrogen (corresponding to incomplete nitration of the cellulose). 
The solvent may evaporate if the solution is spilled, leaving a plastic film that is easily ignited and burns very vigorously. 
Produces toxic oxides of nitrogen during combustion. Used in automobile lacquers and in various coatings.

Nitrocellulose (NC), also called cellulose nitrate, is the oldest thermoplastic. 
Nitrocellulose was invented by Alexander Parkes in 1855 and later commercialized under the trademarks Parkesine, Xylonite and Celluloid. 
Nitrocellulose is synthesized by reacting cellulose fibers with an aqueuos solution of nitric and sulfuric acid. 
The average degree of nitration will be affected by the water content, composition of the bath, immersion time, and reaction condition. 
NC's with about 2 nitrate groups per glucose repeat unit are often chosen in plastics and laquers. 
A higher nitrate content is used in explosives.

Plastics made from NC have excellent mechanical properties including high impact resistant but have poor weathering and heat stability and are not resistant to dilute acids and bases, but are insoluble and stable in water and nonpolar solvents. 
To achieve the desired properties, other additives such as camphor, dyes, stabilizers and fillers are often added.

Nitrocellulose is highly combustable which makes it too hazardous for many applications. 
Today, NC is mainly used as an inexpensive binder in products like (flexographic) printing inks, fast drying lacquers, baked-on enamels, and adhesives.
In several of these applications, NC is modified  (reacted) with other resins such as alkyd and amino resins.
The dilution with other ingredients such as camphor greatly reduces the flammability of NC. This blend is called celluloid. 
Nitrocellulose is used for handles of fountain pens, tools and brushes; for eyeglass frames; and in the past, for motion picture film.

Nitrocellulose is the essential raw material for all propellants and combustible components and is also used for the production of civil explosives.
Nitrocellulose is a nitrate ester of cellulose, produced by the reaction of nitrating acids (consisting of nitric acid and sulphuric acid) with purified cotton linters. 
The nitrocellulose is supplied either water wet or alcoholised.

Nitrocellulose (also called cellulose nitrate) is commonly used in paints, lacquers, wood, paper and metal varnishes, inks for printing on packaging and in making celluloid. 
At room temperature, pure nitrocellulose is a white-yellow solid with an ether-like odour. 
However, industrial nitrocellulose is usually not sold in pure form but damped with water and organic solvents such as isopropyl alcohol, esters, ketones or glycol ethers.
Damped nitrocellulose can be solid or liquid, depending on the amount of damping agent used.

These products form a film simply through the evaporation of the solvents. 
Nitrocellulose basecoatsare used as fillers, while nitrocellulose topcoats are used when a specific look is required. 
Topcoats can be divided into matt, low sheen, gloss and high gloss. 
They feature quick drying properties, surface hardness, workability, ease of application, excellent bonding and an attractive and decorative look, in addition to an exceptionally smooth film. 
Simple thinning is all that’s required for effortless application on both open-pore and closed-pore coating system using a whole host of different application systems with excellent aesthetic results. 
Their use really brings out the natural qualities of the wood used: indeed, they’re very popular for the coating of fine period furniture and elaborate pieces, ultimately providing an infinite array of aesthetic solutions. 

Nitrocellulose or cellulose nitrate is a cellulose derivative.
Nitrocellulose is used in cosmetics, exclusively as a film-forming agent in nail polish and care.
Nitrocellulose is present in plants in large quantities. 
Nitrocellulose is nitrated (originally with nitric acid, but today a mixture of sulfuric acid and nitric acid is used to accelerate the transformation) to form an ester, nitrocellulose, which is then treated with alcohol or water and sold as a moist powder.

In 1832 Henri Braconnot discovered that nitric acid, when combined with starch or wood fibers, would produce a lightweight combustible explosive material, which he named xyloïdine.
A few years later in 1838, another French chemist, Théophile-Jules Pelouze (teacher of Ascanio Sobrero and Alfred Nobel), treated paper and cardboard in the same way.

Around 1846 Christian Friedrich Schönbein, a German-Swiss chemist, discovered a more practical formulation.
As he was working in the kitchen of his home in Basel, he spilled a mixture of nitric acid (HNO3) and sulfuric acid (H2SO4) on the kitchen table. 
He reached for the nearest cloth, a cotton apron, and wiped it up. 
He hung the apron on the stove door to dry, and as soon as it was dry, a flash occurred as the apron ignited. 
His preparation method was the first to be widely used. 
The method was to immerse one part of fine cotton in 15 parts of an equal blend of sulfuric acid and nitric acid. 
After two minutes, the cotton was removed and washed in cold water to set the esterification level and to remove all acid residue. 
The cotton was then slowly dried at a temperature below 40 °C (104 °F).

By coincidence, a third chemist, the Brunswick professor F. J. Otto had also produced guncotton in 1846 and was the first to publish the process, much to the disappointment of Schönbein and Böttger

The patent rights for the manufacture of guncotton were obtained by John Hall & Son in 1846, and industrial manufacture of the explosive began at a purpose-built factory at Marsh Works in Faversham, Kent, a year later. 
The manufacturing process was not properly understood and few safety measures were put in place. 
A serious explosion that July killed almost two dozen workers, resulting in the immediate closure of the plant. 
Guncotton manufacture ceased for over 15 years until a safer procedure could be developed

The British chemist Frederick Augustus Abel developed the first safe process for guncotton manufacture, which he patented in 1865. 
The washing and drying times of the nitrocellulose were both extended to 48 hours and repeated eight times over. 
The acid mixture was changed to two parts sulfuric acid to one part nitric. 
Nitration can be controlled by adjusting acid concentrations and reaction temperature. 
Nitrocellulose is soluble in a mixture of ethanol and ether until nitrogen concentration exceeds 12%. 
Soluble nitrocellulose, or a solution thereof, is sometimes called collodion. 

Guncotton containing more than 13% nitrogen (sometimes called insoluble nitrocellulose) was prepared by prolonged exposure to hot, concentrated acids  for limited use as a blasting explosive or for warheads of underwater weapons such as naval mines and torpedoes.
Safe and sustained production of guncotton began at the Waltham Abbey Royal Gunpowder Mills in the 1860s, and the material rapidly became the dominant explosive, becoming the standard for military warheads, although it remained too potent to be used as a propellant. 
More-stable and slower-burning collodion mixtures were eventually prepared using less-concentrated acids at lower temperatures for smokeless powder in firearms. 
The first practical smokeless powder made from nitrocellulose, for firearms and artillery ammunition, was invented by French chemist Paul Vieille in 1884.

Jules Verne viewed the development of guncotton with optimism. 
He referred to the substance several times in his novels. 
His adventurers carried firearms employing this substance. 
In his From the Earth to the Moon, guncotton was used to launch a projectile into space.

Nitrocellulose is one of the most energetic polymers that have extensive importance in many vital applications. 
Nitrocellulose has proven itself, since it was accidentally discovered, and until now as a pioneering material of great properties that can be used in different fields without faltering. 
In this review article, we will represent an in-depth outlook on Nitrocellulose: its chemical structure & properties, advanced ways of detection and its Nitrogen content, synthesis of some of its forms, and the different forms of applications. 
We have figured out that nitrocellulose is one of the materials that have characteristics ready for continuous enhancement where encouraging results are found.

Nitrocellulose, block, wet, with not less than 25% alcohol appears as a white solid. 
A mixture of the dinitrates and trinitrate of cellulose and ethanol. 
Exposure to heat may evaporate the solvent leaving a residue that is subject to self-accelerating decomposition and may explode if confined or present in large quantities. 
Treat as an explosive. 
Produces toxic oxides of nitrogen when burned.

The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. 
The quality of the cellulose is important. Hemicellulose, lignin, pentosans, and mineral salts give inferior nitrocelluloses. 
In precise chemical terms, nitrocellulose is not a nitro compound, but a nitrate ester. 
The glucose repeat unit (anhydroglucose) within the cellulose chain has three OH groups, each of which can form a nitrate ester. 
Thus, nitrocellulose can denote mononitrocellulose, dinitrocellulose, and trinitrocellulose, or a mixture thereof. 
With fewer OH groups than the parent cellulose, nitrocelluloses do not aggregate by hydrogen bonding. 
The overarching consequence is that the nitrocellulose is soluble in organic solvents such as acetone and esters.
Most lacquers are prepared from the dinitrate whereas explosives are mainly the trinitrate.

The chemical equation for the formation of the trinitrate is:

3 HNO3 + C6H7(OH)3O2 H2SO4 → C6H7(ONO2)3O2 + 3 H2O
The yields are about 85%, with losses attributed to complete oxidation of the cellulose to oxalic acid.

The principal use of cellulose nitrate is for the production of explosives, lacquers, and celluloid. 
The explosive applications are discussed below. 
In terms of lacquers, nitrocellulose dissolves readily in organic solvents, which upon evaporation leave a colorless, transparent, flexible film

As dry nitrocellulose is sensitive to heat and impact, damped nitrocellulose must not be allowed to dry out. 
The container should be tightly sealed when not in use to prevent evaporation of the damping agent and only opened when the contents are ready to be used. 
All the container contents should be used each time.
The quantity of nitrocellulose kept at the processing area should not exceed the amount immediately required for one work-shift.
Do not subject nitrocellulose to heat through direct sunlight, impact or friction. 
Do not allow it to come into contact with acids, alkalis, amines or oxidising agents. 
This could cause it to break down by itself or even ignite.
Always use non-ferrous tools and materials when opening and closing containers of nitrocellulose.
These tools can be made of copper, brass, bronze or wood. 
Tools made of plastic materials should not be used because they tend to produce static electricity. 
The tools and equipment should also be explosion-proof.
Protect all nitrocellulose mixing and processing equipment from static electricity by grounding all metal parts. 
Ground all containers before transferring nitrocellulose.

Membrane filters made of a mesh of nitrocellulose threads with various porosity are used in laboratory procedures for particle retention and cell capture in liquid or gaseous solutions and, reversely, obtaining particle-free filtrates.
A nitrocellulose slide, nitrocellulose membrane, or nitrocellulose paper is a sticky membrane used for immobilizing nucleic acids in southern blots and northern blots. 
Nitrocellulose is also used for immobilization of proteins in western blots and atomic force microscopy  for its nonspecific affinity for amino acids. 
Nitrocellulose is widely used as support in diagnostic tests where antigen-antibody binding occurs, e.g., pregnancy tests, U-albumin tests and CRP. 
Glycine and chloride ions make protein transfer more efficient.
In 1846, nitrated cellulose was found to be soluble in ether and alcohol. 
The solution was named collodion and was soon used as a dressing for wounds.
Nitrocellulose is still in use today in topical skin applications, such as liquid skin and in the application of salicylic acid, the active ingredient in Compound W wart remover.
Adolph Noé developed a method of peeling coal balls using nitrocellulose. 
In 1851, Frederick Scott Archer invented the wet collodion process as a replacement for albumen in early photographic emulsions, binding light-sensitive silver halides to a glass plate.
Magicians' flash papers are sheets of paper or cloth made from nitrocellulose, which burn almost instantly with a bright flash, leaving no ash.
As a medium for cryptographic one-time pads, they make the disposal of the pad complete, secure, and efficient.
Radon tests for alpha track etches use nitrocellulose.
For space flight, nitrocellulose was used by Copenhagen Suborbitals on several missions as a means of jettisoning components of the rocket/space capsule and deploying recovery systems. 
However, after several missions and flights, it proved not to have the desired explosive properties in a near vacuum environment.
In 2014, the Philae comet lander failed to deploy its harpoons due to its 0.3 grams of nitrocellulose propulsion charges failing to fire during the landing.
Nitrocellulose lacquer was used as a finish on guitars and saxophones for most of the 20th century and is still used on some current applications. 
Manufactured by (among others) DuPont, the paint was also used on automobiles sharing the same color codes as many guitars including Fender and Gibson brands, although it fell out of favor for a number of reasons: 
pollution, and the way the lacquer yellows and cracks over time.
Nitrocellulose lacquer was also used as an aircraft dope, painted onto fabric-covered aircraft to tighten and provide protection to the material, but has been largely superseded by alternative cellulosics and other materials.
Nitrocellulose is used to coat playing cards and to hold staples together in office staplers.
Nail polish is made from nitrocellulose lacquer as it is inexpensive, dries quickly, and is not damaging to skin.
Nitrocellulose lacquer is spin-coated onto aluminum or glass discs, then a groove is cut with a lathe, to make one-off phonograph records, used as masters for pressing or for play in dance clubs. 
They are referred to as acetate discs.
Depending on the manufacturing process, nitrocellulose is esterified to varying degrees. 
Table tennis balls, guitar picks, and some photographic films have fairly low esterification levels and burn comparatively slowly with some charred residue.
Guncotton, dissolved at about 25% in acetone, forms a lacquer used in preliminary stages of wood finishing to develop a hard finish with a deep lustre.
Nitrocellulose is normally the first coat applied, sanded and followed by other coatings that bond to it.

Table tennis ball, prepared from nitrocellulose (Celluloid)
Because of its explosive nature, not all applications of nitrocellulose were successful. 
In 1869, with elephants having been poached to near extinction, the billiards industry offered a US$10,000 prize to whomever came up with the best replacement for ivory billiard balls. 
John Wesley Hyatt created the winning replacement, which he created with a new material he invented, called camphored nitrocellulose—the first thermoplastic, better known as Celluloid. 
The invention enjoyed a brief popularity, but the Hyatt balls were extremely flammable, and sometimes portions of the outer shell would explode upon impact. 
An owner of a billiard saloon in Colorado wrote to Hyatt about the explosive tendencies, saying that he did not mind very much personally but for the fact that every man in his saloon immediately pulled a gun at the sound.
The process used by Hyatt to manufacture the billiard balls, patented in 1881, involved placing the mass of nitrocellulose in a rubber bag, which was then placed in a cylinder of liquid and heated. 
Pressure was applied to the liquid in the cylinder, which resulted in a uniform compression on the nitrocellulose mass, compressing it into a uniform sphere as the heat vaporized the solvents. 
The ball was then cooled and turned to make a uniform sphere. 
In light of the explosive results, this process was called the "Hyatt gun method".

Nitrocellulose is a product that has found many uses in everyday life. 
Nitrocelluloses physical form can vary widely from white fibers to thin sheets to thick liquid.
Nitrocellulose is used to make everything from smokeless gun powder to waterproof fuses in pyrotechnics, inks, adhesives, varnishes, resins, lacquer coatings, embedding sections in microscopy, photography, electrotechniques, galvanoplasty, and even certain plastics, such as what is used in ping-pong balls. 
Nitrocellulosecan be a white, yellow, or transparent plastic, which can be anywhere from brittle to flexible. 
Nitrocellulose can have properties ranging from a strong, resistant plastic to an unstable class B (highly flammable, explosive when confined) explosive material, all determined by the nitrogen content. 
Other current uses include the making of membranes that are used to immobilize DNA, RNA, or protein, which can then be probed with a labeled sequence or antibody (Western blot assays), microscopy embedding, electrotechniques, skin protectants, microfilters, and others. 
Nitrocellulose continues to be used in photography, the manufacture of lacquers, patent and natural leathers, artificial pearls, process engraving, and cements.

IUPAC NAME:

cellulose nitrate

SYNONYMS:

pyroxylin.
nitrocotton.
pyroxyline.
guncotton.
cellulose ester.
cordite.
celluloid.
cellulose nitrate.