In the following reaction: Cellulose \(\frac{\text { (i) } \mathrm{CS}_{2} \mathrm{~N} \mathrm{~N} \mathrm{OH}}{\text { (ii) } \mathrm{HCl} / \mathrm{HOH}}{\longrightarrow}[\mathrm{P}]\) Here, the product [P] is (a) Rayon (b) Cellulose acetate (c) Gun cotton (d) Cellulose xanthate

Rayon is a versatile fabric often celebrated for its silk-like feel, which is primarily derived from cellulose, a natural component of plant cell walls.

The creation of Rayon begins by extracting and purifying cellulose from wood pulp, typically obtained from softwoods like pine or spruce. The purified cellulose is then solubilized through a process known as xanthation, which involves reacting the cellulose with carbon disulfide in the presence of sodium hydroxide. This reaction produces cellulose xanthate, a key intermediate in Rayon synthesis.

The resultant viscous solution, often referred to as 'viscose,' can then be spun into fibers. By forcing this viscose through spinnerets into an acid bath, the cellulose xanthate reconverts back to cellulose while forming fine filaments. These filaments are coagulated into fibers and can be cut into various lengths for different applications.

The final product, Rayon, is then washed, purified, and sometimes treated to enhance its properties such as strength, texture, or dye affinity. Despite being made from a natural polymer, the extensive chemical processing classifies Rayon as a semi-synthetic fiber.

Cellulose xanthate, pivotal in the creation of Rayon, is crafted through a chemical reaction known as xanthation.

The starting material, cellulose, does not dissolve in water or most organic solvents, which poses a challenge in fiber formation. To overcome this, chemists convert cellulose into a soluble derivative. In this case, cellulose reacts with carbon disulfide (CS₂) in an alkaline medium containing sodium hydroxide (NaOH). This results in the production of cellulose xanthate.

The specific conditions, including temperature and the ratio of reagents, are carefully controlled to ensure successful xanthate formation. The mixture's ph is also crucial - it must remain alkaline throughout the process. The xanthate is soluble in the resultant viscous liquid, making it possible to extrude it through a spinneret to form fibers.

It's important to note that the cellulose xanthate is not stable at high temperatures or over long durations, so it must be processed relatively quickly into Rayon fibers to avoid degradation.

Semi-synthetic materials bridge the gap between wholly natural and fully synthetic products. They originate from naturally occurring polymers, such as cellulose but undergo significant chemical processing to alter their properties for specific applications.

An excellent example of a semi-synthetic material is Rayon, produced from natural cellulose. Rayon's fabrication process, which includes solubilizing cellulose via chemical modification and regenerating the fibers, substantially alters the original form of the cellulose. Similarly, cellulose acetate, used in photographic film and eyeglass frames, and cellulose nitrate, known as gun cotton, are other instances of semi-synthetic materials derived from cellulose.

The properties of semi-synthetic materials can be tailored by adjusting the chemical process variables, making them highly versatile. They are often designed to mimic natural materials like cotton, silk, or wool but can be engineered for improved characteristics such as increased strength, enhanced colorfastness, and reduced cost.