Cellulose acetate is one of the first synthesised plastics and is used as a film base, a fibre that can be woven into fabric and as a plastic. Cellulose acetate is produced from processed wood pulp, agricultural refuse or cotton fibre. Cellulose acetate is also called triacetate and acetate. Cellulose acetate is made from renewable resources, resists mildew and mould, and may be washed or dry cleaned without shrinking. The process for preparing cellulose acetate in the lab is similar to producing it in the factory.
After putting on eye protection, add 20 millilitres of glacial acetic acid, 5 millilitres of acetic anhydride and three drops of sulphuric acid into a flask. The sulphuric acid is a catalyst for the reaction. Mix the ingredients with a glass rod.
Place 0.5 grams of cotton into the flask. Ensure the cotton is fully submerged in the solution. Place the stopper lightly on the flask. The reaction takes about 8 hours and is complete when the cotton is fully dissolved.
Gently pour the solution into a beaker containing 100 millilitres of distilled water. The cellulose acetate will precipitate out of solution, looking like clear filaments and globules in the water.
Pour the water and cellulose acetate gel into a funnel containing filter paper. The cellulose acetate will collect on the filter paper. If doing this experiment in a laboratory, filtering will be accelerated using a vacuum filter apparatus.
Scrape the cellulose acetate off the filter paper into a test tube, using the glass rod. Add chloroform in the test tube to dissolve the cellulose acetate. Pour the dissolved cellulose acetate onto a glass dish. Allow the chloroform to evaporate. The resulting thin film is cellulose acetate plastic.
Always wear eye protection when conducting experiments. For best results, evaporating the cellulose acetate and chloroform solution on glass should be completed in a dust-free environment. For additional hand protection, latex or vinyl gloves may be worn.
This is a dangerous experiment and should only be conducted in a fully stocked laboratory with proper safety equipment. Glacial acetic acid, acetic anhydride, sulphuric acid and chloroform are highly reactive and toxic. This experiment should be conducted under a vent hood, as the compounds are irritating to mucous membranes in the nose and lungs.