Question

Which among the following is NOT a semi-synthetic polymer?
A. Terylene
B. Viscose-rayon
C. Cupra-ammonium silk
D. Acetate rayon

Answer 1

Hint: The synthetic polymers are defined as those polymers which are synthesized in the laboratories while the semi-synthetic polymers are obtained from the natural polymers by chemical means.

Complete answer:
-Polymers are the class of molecules which comprises a long chain of molecules formed by large molecules known as macromolecules which is further formed from a small unit known as monomers.
-The polymers based on their formation are divided into natural polymer or synthetic polymer.
-The natural polymers are those polymers which occur naturally. The examples of natural polymers are protein, cellulose.
-The synthetic polymers are those polymers which are prepared in the laboratories by artificial means. The examples of synthetic polymers are Buna-S, Poly vinyl chloride (PVC).
-Semi synthetic polymers are obtained from natural polymers by chemical modification.
-Terylene is a synthetic polymer which is obtained by the reaction of ethylene glycol with terephthalic acid.
-Viscose rayon is a semi-synthetic polymer formed from the naturally occurring cellulose which is a natural polymer.
-Cupra-ammonium silk is a semi-synthetic polymer which is obtained by dissolving cupra ammonium solution with the cellulose which is a naturally occurring polymer.
-Acetate rayon is a semi-synthetic polymer which is formed from cellulose acetate.
Thus, among the given polymer terylene is not a semi-synthetic polymer.
Therefore, the correct option is A.

Note:
Terylene is also known as Dacron. The cellulose acetate shows similarities with viscose rayon and was treated as the same textiles but rayon resists heat whereas acetate usually melts easily.