X appears like silk. It is strong and flexible. Non availability of x caused riots after world war II. What is x and why?

Rayon ;Rayon is a manufactured regenerated cellulose fibre. It is made from purified cellulose, primarily from wood pulp, which is chemically converted into a soluble compound. It is then dissolved and forced through a spinneret to produce filaments which are chemically solidified, resulting in synthetic fibres of nearly pure cellulose.Because rayon is manufactured from naturally occurring polymers, it is considered a semi-synthetic fibre.