Cellophane

Cellophane is a bioplastic wrapping material. It is a thin, transparent sheet made of cellulose. It has low permeability. That means very little air, oils, greases, bacteria, and water can get in. That makes it useful for food packaging.

Cellophane was invented by Swiss chemist Jacques E. Brandenberger. 
It took ten years for Brandenberger to perfect his idea. He added glycerin to soften the material. By 1912 he had built a machine to make the film. He called the product "Cellophane", from the words cellulose and diaphane ("transparent"). Cellophane was patented that year.Carlisle, Rodney (2004). Scientific American Inventions and Discoveries, p.338. John Wiley & Sons, Inc., New Jersey. .

DuPont built the first cellophane manufacturing plant in the US. One of their chemists found a way to make it moisture proof. The material became hugely popular.

"Cellophane" is a general term in some countries, but in other countries it is a registered trademark.

Cellophane played a crucial role in developing the self-service retailing of fresh meat. The transparency helped customers see the quality of meat before buying. Cellophane also largely prevents discoloration of food.

 Preparation 
 Viscose method 
The most common way of purifying cellulose is the viscose method. This takes a source of impure cellulose, usually wood pulp, and treats it with carbon disulfide and a strong base like sodium hydroxide to make a soluble cellulose xanthate, also called viscose. The solution can then be filtered and treated with a strong acid like sulfuric acid to precipitate the purified cellulose.

 References 

Category:Polymers
Category:Synthetic materials
Category:Cellulose derivatives
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