Who knows what Celulu is? What is the function?

It should be celluloid, a plastic made of collodion (nitrocellulose with low nitrogen content), plasticizer (mainly camphor), lubricant and dye. Horny, transparent and tough. It is thermoplastic and softens at 80 ~ 90℃. Water resistance, dilute acid resistance, weak alkali resistance, salt solution resistance, hydrocarbon resistance, oil resistance, etc. But concentrated acid, strong alkali and many organic solvents can dissolve or destroy it. Easy to catch fire. Can be made into beautiful products, such as stationery, toys, table tennis. ...

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Now speaking of plastics, who knows? But what is celluloid? Some people may be speechless. In fact, celluloid is the ancestor of plastic, and celluloid is the transliteration of English "celluloid", which has two meanings: one is fake ivory; The second kind is called movies. You may think, what does celluloid have to do with these two things? But looking at history really matters. Everyone who loves sports knows billiards. In the past, billiards were mostly the entertainment of the rich. In the19th century, billiards became very popular in America. Billiards at that time were made of ivory, which was very elegant. But at that time, the number of elephants in Africa was decreasing, and it was difficult for the United States to get ivory to make billiards, which worried the owners of billiards factories. So it was announced that whoever could invent a billiard material instead of ivory would get a prize of $65,438+0,000. This was not a small sum at that time.

There is a saying that "there must be a brave man under the four rewards", which is not completely in line with the facts, but it is a bit irritating. 1868, there was a man named John Hayat in Albany, USA. He is a printer, but he is also interested in billiards, so he decided to invent a material to make billiards instead of ivory. He thinks day and night. At first, he added natural resin shellac to the sawdust to make it agglomerate and roll into balls, which looked like ivory billiards, but it broke when touched. I don't know how many things I tried later, but I didn't find any hard and unbreakable materials.

Many things happen. One day, he found that nitrocellulose, the raw material of gunpowder, was dissolved in alcohol and then coated on objects. After drying, a transparent and strong film could be formed. He tried to condense the film into balls, but failed again and again in the experiment. To say that Hayat is really an indomitable person, he didn't lose heart and continued to explore as always. Finally, in 1869, he found that nitrocellulose became a hard and brittle material with good flexibility after adding camphor to nitrocellulose. Products with various shapes can be made under hot pressing, which can really be used to make billiards. He named it celluloid.

It is said that Hyatt didn't get the prize of $654.38 million. But this is a piece of cake for him, because at this time he has become a great inventor, and he will get more benefits by virtue of his invention. 1872, he established a celluloid factory in Newark, USA, which was not only used to produce billiards, but also used to make windshields and films for cars and cars, creating a precedent for the plastic industry. From 65438 to 0877, Britain also began to use celluloid to produce fake ivory, billiards and other plastic products. Later, Hyatt used celluloid to make boxes, buttons, rulers, table tennis and glasses frames.

Since then, various types of plastics have emerged one after another. At present, there are more than 300 kinds of industrialized plastics, and more than 60 kinds are commonly used. As for all kinds of products produced with these plastics, there are countless, covering all sectors of the national economy. Who doesn't have plastic products now?

A small billiard ball, due to the lack of raw materials, can actually derive a new material all over the world, which has many philosophies worth thinking about. Students who are interested in invention can certainly get inspiration from it.

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Nowadays, colorful plastic products abound in production and people's lives, but more than a century ago, we only relied on natural plastic materials-hair, claws, keratin and so on as raw materials to produce combs, windshields, brushes, buttons and other traditional craft products. Obviously, the emergence and development of plastic industry is the same as other chemical products. Experienced a process of self-development.

First, the research caused by the "ivory problem"

More than a century ago, when the use of bones, hooves, tortoise shells and other products to produce "natural plastic substances" was abandoned, the demand for ivory increased day by day. At that time, in order to obtain ivory, more than 20 thousand elephants were killed every year, worth as much as 2 million pounds. Although the ivory output of each elephant is very low, and poaching and trading are not allowed by law. Today, ivory carving is still common in Africa and Asia. Ivory is made from animals such as walrus.

The tusks and other parts of the teeth of walrus and hippopotamus (hippopotamus), but the most difficult and eager thing is the ivory obtained from the elephants in West Africa, so the elephants in West Africa have suffered the greatest misfortune and have to be protected. However, poachers continue to kill thousands of elephants every year, not for meat, but for their valuable teeth. Unexpectedly, Dr. David Livingstone (1813 ~1871), a Scottish missionary and researcher, thinks that the supply of elephants is inexhaustible. Fortunately, the British brothers D. Spill and A. Parks, and the American brothers J.W.Hyatt Ete and I.S.Hyatt Ete are not confined by the above views. They tried to solve this "ivory problem" by researching and inventing substitute substances, which led to the appearance of fake ivory-celluloid.

Second, the earliest "natural plastic substance"

Fibrin, such as hair, hooves and feet, keratin and feathers, is a polymer with high sulfur content. They are insoluble in solvents and chemicals and have relatively no chemical effect. These natural plastics can be shaped by soaking in hot water and then cooling to room temperature. Cattle hoof is a kind of solid material that is often easy to obtain in the production of buttons. /kloc-in the 0/8th century, the old manufacturing technology was replaced by hot-pressing die technology, which was used to manufacture buttons by grinding shoes and feet, because the natural rubber existing in stilts was suitable as the adhesive for forming buttons.

1760, American E. Noyes made a decorative comb with hoofs and feet. At that time, Leo Munster in the United States became a famous "comb city". Lemmingster has concentrated a number of carding machine factories, thus developing many plastic manufacturing instruments, which are still in use after continuous improvement. Due to the gathering of carding factories, Yingmingster became the earliest plastic "capital" in the United States.

As for the "Comb City", it is actually Changzhou City, Jiangsu Province, China and Chendu Bridge, Wujin County, which belongs to this city. Its traditional product comb comb, as early as more than 3000 years ago, was very famous in Shang Dynasty. In addition, there is a saying that "hair is short and difficult to comb" in Yang Xiong's Poem of Changyang in the Western Han Dynasty, and there are also good sentences in Du Fu's poem "Water Hosts Send Prosperous Men". The earliest combs in China may also be made of natural plastic materials such as bamboo, hooves and feet. Changzhou's combs won gold medals in international fairs such as Philadelphia, Leipzig and Panama in the Qing Dynasty. Known as the "famous comb", after liberation, with the emergence of a new synthetic material industry. Comb production has been further developed. Not only do they sell well all over the country, but they are also exported to more than 20 countries such as Europe and Southeast Asia, so the real "comb city" in the world should be in China.

Third, the synthesis of nitrocellulose-celluloid

Hydroxyl groups in cellulose molecules react with nitric acid to form esters, which are called nitrocellulose. It is made of nitrocellulose (cotton in most cases).

According to the ratio of nitrogen in the above reaction molecules is 14. 14%, the nitrogen content of nitrocellulose produced in industry is always lower than this theoretical value. That is to say, not all hydroxyl groups in cellulose molecules are esterified by nitric acid, and only some hydroxyl groups react with nitric acid. The nitrogen content of cellulose with high nitrification degree is 12.6- 13.4% (cellulose with high nitric acid ratio is called cannon cotton), which is easy to burn and explode. It is the main raw material of smokeless powder. It can also be used to produce nitrolacquer. Nitrocellulose with low nitration degree and nitrogen content of10-1%is called collodion cellulose, and its ethanol and ether solution is collodion (or collodion) commonly used for bottle sealing.

In 1869, J.W. hyatt1837 ~1920 tried to make an ivory substitute for billiards by co-heating the mixture of nitrocellulose, camphor and ethanol under high pressure and then hardening it under normal pressure. The first synthetic plastic he develope is a tough material, which has great tensile strength, water resistance, oil resistance and acid resistance, and can produce product of various colors at low cost, thus opening up a road for that development of modern plastic industry.

It should be pointed out that F.H. Conrath (F.H. Braconnot 178 1 ~ 1855) and T.J. Pi Lai Ci (T.J. Peloze 1807 ~ 65435) are inventions. 1846, C.F.Schonbein of Switzerland treated cellulose with mixed acid of sulfuric acid and nitric acid as nitrating agent to generate cellulose derivatives, which Schebein called collodion and could be used as explosives.

Fourthly, the road to success in creating dental products.

Hyatt Brothers achieved the success of celluloid products through the dental specialty of Rubber Trust. 1870, they established Albany Denture Company to produce celluloid dentures. After their success, they registered a trademark at 187 1 and named it celluloid, and established a celluloid manufacturing company in Albany, USA. At 1872, they put it.

/kloc-at the end of 0/8 and the beginning of++century, celluloid was used in many aspects, such as making combs, toothbrushes, collars, movie toys, car windshields, piano keys, photographic films and other consumer goods. 1890, photography in America popularized and promoted the development of film production technology and film industry. Unfortunately, due to fire or wear and tear, many historic early activity photographs were once made of celluloid. Although celluloid has been replaced by new synthetic polymer materials in many aspects because of its easy combustion, celluloid continues to be produced and widely used in Europe, the former Soviet Union, the United States and Japan.

To sum up, celluloid, as the early king of plastics, was replaced by synthetic polymers, but it was still used in table tennis and collodion. Celluloid was once used as a patented product, such as spectacle frames, pens, safety (unbreakable) glass, billiards and so on. Tracing back to the history of plastic development, the fact that celluloid was invented, especially finding a substitute for ivory, is worthy of praise from the scientific and technological circles!

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Chinese name: celluloid

English name: celluloid

English Name 2: Nitrocellulose Plastics

Appearance and performance: colored or colorless transparent or opaque sheet, soft and elastic.

Melting point (℃): No data available.

Boiling point (℃): No data available.

Relative density (water =1):1.35 ~1.60.

Flash point (℃): No data available.

Ignition temperature (℃): 180

Solubility: insoluble in water, benzene and toluene, soluble in ethanol, acetone and ethyl acetate.

Main uses: mainly used for making table tennis, glasses frames, toys, pens, decorations, etc.

Other physical and chemical properties:

Health hazards: No data available.

Danger of explosion: This product is flammable.

Hazard characteristics: easy to burn in case of open flame and high heat. Storage for a long time will gradually heat up, and if the accumulated heat does not dissipate, it will cause spontaneous combustion.

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