Cuprammonium rayon

Brown cupra (also known as cupro or Bemberg) fabric made of rayon
Lab demonstration of the process. When a solution of cellulose in cuprammonium hydroxide comes into contact with sulfuric acid, the cellulose begins to precipitate from the solution. The sulfuric acid reacts with a complex compound of copper and dissolves it. Thin blue fibers of rayon are formed. After some time, sulfuric acid reacts with the complex compound and washes out the copper salts from the fibers. The fibers become colorless.

Cuprammonium rayon is a rayon fiber made from cellulose dissolved in a cuprammonium solution,[1] Schweizer's reagent.[2]

It is produced by making cellulose a soluble compound by combining it with copper and ammonia with caustic soda. The solution is passed through a spinneret and the cellulose is regenerated in hardening baths that remove the copper and ammonia and neutralize the caustic soda. Cuprammonium rayon is usually made in fine filaments that are used in lightweight summer dresses and blouses, sometimes in combination with cotton to make textured fabrics with slubbed, uneven surfaces.[3]

The fabric is commonly known by the trade name "Bemberg", owned by the J.P. Bemberg company. The fabric may also be known as "cupro" or "cupra". It is also known as "ammonia silk" on Chinese fashion retail websites.[citation needed]

  1. ^ "cuprammonium rayon". Retrieved December 1, 2011.
  2. ^ Burchard, Walther; Habermann, Norbert; Klüfers, Peter; Seger, Bernd; Wilhelm, Ulf (1994). "Cellulose in Schweizer's Reagent: A Stable, Polymeric Metal Complex with High Chain Stiffness". Angewandte Chemie International Edition in English. 33 (8): 884–887. doi:10.1002/anie.199408841.
  3. ^ "Rayon Fiber". Archived from the original on April 6, 2008. Retrieved December 1, 2011.