Cellulose chemistry is one of main foundations from which polymer industry was born. But initially nitrocellulose-based compounds were very flammable, even explosive, greatly limiting their use. As this problem was gradually solved by chemists, scope of use of this chemical substance, as well as form of use of this material, was expanded. One of substances that had a huge impact in the first half of 20th century was cellophane (cellophane).

 

Cellophane was inspired by Swiss chemist Jacques Brandenburg. Story goes that in 1900, while dining at a restaurant, Brandenburg observed spilled red wine stain a white tablecloth and began thinking about developing a protective coating.
Material is based on cellulose chemistry, takes advantage of Charles Cross and Edward Bevan's 1892 advancement of reacting wood cellulose with caustic soda and carbon disulfide, producing a golden-yellow viscous liquid called viscose. While early products using material were similar to celluloid, such as combs and handles, Cross and Bevin focused on making fibers useful in textile industry.
Initial experiments produced a fiber that was too brittle to be a useful substitute for natural fibers. However, through a series of lucky accidents, it was discovered that viscosity of material increases over time, a process known as maturation. This resulted in a stronger, more ductile product that could be easily spun, later known as rayon. But rayon, called cellulose xanthate, is far less flammable than nitrocellulose.

 

Brandenburg chose viscose as a coating material for cotton fabrics to make them resistant to staining. He also had problems with very rigid and fragile structures. For several years, he worked on making thinner films out of cellulose xanthate, and end result is what he calls cellophane.
Brandenburg was well aware of flammability problems of celluloid film used in movies, and he first tried to replace celluloid on the market with his own cellophane. However, he soon discovered that cellophane deformed badly at high temperatures and was too stiff to create precise sprocket holes in film.
But it turns out that cellophane is ideal packaging material. Transparent, lightweight, and tough, it was far superior to the two packaging materials commonly used at the time: gelatin and tin foil. The first products packaged in cellophane were perfumes, soaps and toothpaste. Brandenburg targeted food industry, but during World War I, mass production of cellophane shifted to gas masks due to its gas barrier properties. It is also used as a transparent surgical dressing for wounds.
After end of First World War, consumer market began to develop again. The Whitman Chocolate Company had adopted cellophane as a packaging material for some chocolates in 1912, but in the early 1920s, cellophane was not a good moisture barrier as its use expanded to products such as baked goods and tobacco .
During this time, a French company founded by Brandenburg sold rights to use cellophane to DuPont, and a DuPont chemist developed a solution to moisture problem. Ironically, William Hale Charch created a coating based on nitrocellulose.
It also incorporates a plasticizer to adjust properties of coating, and a wax for moisture resistance. Completed in 1927, development took three years and was beginning of DuPont's long history of chemical innovation. Once moisture barrier was resolved, cellophane usage exploded, making it one of DuPont's most successful and well-known products.
During same period, another form of chemically modified cellulose laid foundation for development of early thermoplastics. In 1865, French chemist Paul Schutzenberger first synthesized cellulose acetate by reacting cellulose with acetic anhydride.
Although cellulose acetate is basically a thermoplastic, it is impossible to melt process because its decomposition temperature is below its softening point. However, in 1903, German chemists Arthur Eichengrun and Theodore Becker discovered that cellulose acetate would dissolve in acetone and developed a soluble form of cellulose acetate.
A year later, brothers Camille and Henry Dreyfus began working in a laboratory in Basel, Switzerland. Their attention turned to cellulose acetate, and they created a paint called "paint" for fabric and wooden planes of the day, making them resistant to effects of moisture and fire. In 1913, just as process for making cellophane was improving, Dreyfuss brothers established Cellophane Company to produce films and cellulose acetate-based paints.
They were just beginning to develop a process for extracting fibers from acetate, and during World War I they shifted all their efforts to making cellulose acetate paint. To this end, they built a factory in Derbyshire, England. During war, Camille Dreyfus went to United States at the request of U.S. government to build a cellulose factory.
After the war, Dreyfus brothers resumed their acetate development, which they called Celanese, and British company's name was changed to British Celanese in 1923. In 1927, American Dreyfus Company established Amcelle, which acquired Celluloid Company in Newark, New Jersey, which was renamed American Celanese Company.
In 1931, Celanese developed a melt-processable cellulose acetate using same chemistry as plasticizer Waldo Semon had used to solve PVC processing problems five years earlier. In the same year, it was discovered that by replacing most of acetic anhydride with propionic acid, it was possible to prepare cellulose acetate propionate (CAP), a compound that is more impact-resistant and requires less plasticizer to make it melt processing.
Further improvements were achieved in 1938 when butyric acid was used in a reaction to produce cellulose acetate butyrate (CAB). This material not only exhibits better toughness, but also has better heat resistance than CA and CAP.

 

Lego bricks are now mostly made of ABS, originally injection molded from cellulose acetate.
Celanese has a long and rich history in polymers and still includes several grades of cellulose acetate in its products. But company with a wide range of products in cellulose space bears name of Eastman, another pioneer in the early days of cellulose development. By far the most famous application is transparent screwdriver handle.

 

But cellulose remains an important contributor to coatings, paints and varnishes. These materials are used in clothing and curtains in fiber form and are also materials of choice for cigarette filters. Performance-wise, prize ribbons are made almost entirely of cellulose acetate, a material still used in many playing cards. Lego bricks are now mostly made of ABS, originally injection molded from cellulose acetate.
Most of market share of cellulose has been taken away by other materials. Cellophane was largely replaced by polyethylene, polypropylene, PVC, and polyvinylidene chloride (PVDC), another polymer discovered by accident in the early 1930s, this time thanks to Dow Chemical Company (Dow Chemical). Cellulose acetate fibers are replaced by nylon and polyester.
Interestingly, now that plastics industry is focusing on sustainability and circular economy, a polymer that can be derived from anything that contains cellulose is starting to gain new attention. In an age where researchers are trying to make polymers out of anything with a biological lineage, it will be interesting to see if we can go back to our roots.