How to Make Rayon Fibers From Filter Paper

Rayon is a manufactured fiber composed of cellulose.

Rayon is a fiber produced from cellulose. It was the first man-made fiber, but it is not considered synthetic in the sense that petroleum-based fibers such as nylon or polyester are. It was originally called artificial silk and was developed in the late 1800s in France. Today it is made from the cellulose extracted from wood pulp. The fabric made from Rayon fibers is similar in absorbency, breathability and drape to natural fabrics like cotton and linen. You can make rayon in the laboratory as a chemistry exercise, but you will not be able to use the results to make fabric.

Things You'll Need

• Safety glasses
• Gloves
• Scientific scales
• Fume hood
• 10g basic copper carbonate (CuCO3.Cu(OH)2.H2O)
• 100cc concentrated 880 ammonia solution
• 2 beakers, 250cc
• Glass stirring rod or magnetic stirrer
• Scissors
• 2g filter paper
• 500cc sulfuric acid
• Beaker, 1 dm3
• Syringe

Instructions

1. Put on safety glasses and protective gloves. Do not attempt this exercise without this safety equipment.

2. Measure 10g basic copper carbonate into a 250cc beaker. In a well-ventilated area or under a fume hood, add 100cc of 880 ammonia solution. Stir for 2 minutes with a glass rod or use a magnetic stirrer if one is available. Let the mixture settle.

3. Pour the deep blue solution into a second 250cc beaker, leaving the sediment behind. The solution contains tetraamminecopper(II).

4. Cut 2g of filter paper into squares smaller than your fingernail. Add a few pieces at a time to the tetraamminecopper(II) solution. Stir after each addition. Continue adding the filter paper until the solution becomes a thick gel. You will use about 1 1/2g of the filter paper. Stir to remove lumps. Do not let any air bubbles become trapped in the gel. It may take up to an hour for the filter paper to dissolve completely. The gel is called viscose.

5. Put 500cc of sulfuric acid into a beaker with 1 cubic decimeter (1 dm3) capacity.

6. Draw some of the viscose into a plastic syringe. Do not draw in any lumps. Put the end of the syringe into the sulfuric acid and inject the viscose into it. Blue rayon fibers will form which will gradually turn white because the acid destroys the tetraamminecopper(II), neutralizing it.

7. Take the rayon fibers out of the sulfuric acid after a few minutes and wash under a stream of clean water.

Tips & Warnings

• In manufacturing rayon fabric, the blue solution goes through spinnerets is hardened in a bath that removes any remaining ammonia and copper.

• You can use a hypodermic needle attached to the syringe to form smaller fibers. Use caution in handling the needle. Attach it to the syringe after you draw up the blue gel.

• If you are teaching this experiment, consider preparing the cellulose solution before class. This saves about 15 minutes. You might also want to prepare some rayon fibers in case the demonstration fails in class.

• Handle the chemicals with extreme care. Wear safety glasses and gloves and do not let the chemicals come into contact with your skin. Do not inhale any of their fumes. Basic copper carbonate is classified as "Harmful" and concentrated 880 ammonia solution is classified as "Corrosive" and a "Danger to the environment." Sulfuric acid is an "Irritant" at the concentration used in this exercise.

References

• Ohio State University: Rayon the Multi-Faceted Fiber; Joyce A. Smith, Ph.D.
• Practical Chemistry: Making Rayon
• ICBSE.com: Chemistry Project to Prepare Rayon Threads From Filter Paper