John Wesley Hyatt; an inventor and printer in the US created in 1870, a highly flammable synthetic plastic. This is my attempt to recreate his composition which became known as Celluloid to celebrate Chemistry and Christmas 2015.
The story of Celluloid fascinates me and if you want to find out more please continue reading below. Otherwise enjoy the video of specially treated Celluloid Christmas trees.
WARNING: HIGHLY FLAMMABLE: ignite on top of fire-proof mats/material and keep any other flammable substances away from the area
HISTORY AND FACTS ABOUT CELLULOID
The history of the first available commercial synthetic plastic has always fascinated me. Before the introduction of Celluloid in America, British chemist Alexander Parks created Parkesine, a new man-made cellulose nitrate plastic. The only source of naturally occurring ‘plastic’ products at that time came from cow’s hoofs, ivory, bones, and tortoiseshell. These included combs, buttons, buckles and brush handles just to name a few.
The development and rise of Celluloid as the new wonder material in the late 1800’s was catalysed by the need to find a substitute for ivory. Ivory was in great demand in the early 18th century, not only as a precious material for carving but for the production of billiard balls. So much so, that the low yield of ivory obtained from the tusks and teeth of animals (usually illegally by poachers); led to the West African elephant being considered an endangered species and almost drove them to the brink of extinction.
By the 1850’s the nitration of cellulose; a natural polymer comprised of several glucose molecules was well known as guncotton and was used as an explosive. Cellulose is a polysaccharide which is present in the cell walls of green plants and has been used in paper production for over 2000 years. It is insoluble in common solvents, but by nitrating it, it became cellulose nitrate and was now easier to dissolve it in a 50:50 mixture of ethanol and ether (known as Collodion), acetone, ethyl acetate, butyl acetate, etc. One of its first applications around the 1840’s was as a coating for wounds and surgical cuts and in photography.
In 1870 the American inventor and printer John Wesley Hyatt thought he had produced a useful substitute for the ivory used for making billiard balls. Thanks mainly to a 10,000 US dollars prize offer (3 million in today’s money) to whoever came up with a useful alternative to ivory. Hyatt developed a moulding hot compression method using cellulose nitrate and camphor, which was added as a plasticizer and called this new plastic Celluloid. Camphor is a white solid ketone (C6H16O6) obtained from the steam distillation of wood of the tree Cinnamomum camphora or from turpentine. It is utilised as a flexible agent or plasticizer which reduces the intermolecular hydrogen bonding between polymer chains, such as those present in cellulose nitrate making it more pliable and minimising the tendency to break or bend.
From then on, production skyrocketed and applications expanded everywhere. For example, George Spill and company produced waterproof textiles in competition with Mackintosh rainwear (successful to an extent although highly flammable). Hyatt saw an opportunity in the dental trade and produced Celluloid dental plates (which became soft and melted overtime with the heat inside the mouth). He also started production of Celluloid billiard balls (the catalyst that really started this whole revolution). In the end, these new billiard balls were not as good as the original and often caught fire when placed near glowing cigarettes and even exploded when two or more balls collided with enough force.
In spite of these setbacks, progress was made in moulding techniques which in the early 1900’s brought cheap and mass produced alternative thermoplastic products such as knife handles, toothbrushes, combs, etc. which were indistinguishable from the natural source. Later applications and perhaps the most remembered ones include piano keys and photographic film.
Celluloid photographic film was a huge success but it had a main drawback, it was highly flammable. It would spontaneously combust with the heat given out by the projector and decayed quickly releasing nitrogen oxide gases and nitric acid. It was later replaced by the much safer cellulose acetate and then polyester film.
The development of man-made fiber industries (by the extrusion of filaments through small orifices called spinnerets) and discovery of other cellulose plastics such as cellulose acetate used in rayon continued to push the boundaries of applications. Unfortunately, the golden years of Celluloid were numbered. A new synthetic plastic, more durable, safe and a more versatile material was going to replace Celluloid. This new plastic was Bakelite named after the inventor Leo Hendrick Baekeland, produced from the controlled condensation polymerisation of phenol and formaldehyde. Bakelite ended up replacing typical Celluloid and shellac applications from billiard balls to early phonograph records and telephones. Even today, Bakelite products are much sought after by collectors.
Sadly, there are no Celluloid billiard balls or even celluloid photographic film today but Celluloid can still be found in some ping-pong or table tennis balls and cellulose nitrate (apart from guncotton and smokeless powder) is still available and generally used as a lacquer for guitar and wood finishing to develop a deep and warm lustre.
Seymour, R. B.; Kauffman, G. B.; J. Chem. Edu., Volume 69, Number 4, April 1992 pp. 311-314.
Great video on INJECTION MOULDING and how plastic objects are made today: