Question

Which of the following is a natural polymer?
1. $Buna - S$
2. $Proteins$
3. $PVC$

Answer 1

The naturally occurring polymers, from plants, animals and surroundings are known as natural polymers while the polymers which are synthesized under the supervision of scientists and engineers in the lab are known as synthetic polymers.

Complete step by step answer:
The polymers which are obtained naturally without any interference of humans are known as natural polymers. They are simply extracted from nature and utilized. Some of the natural polymers are as follows: silk, wool, DNA, cellulose, protein, pectin and many more.
The polymers which are extracted from oil and petroleum with the help of engineers and scientists are known as synthetic polymers. The natural products are processed in labs with artificial equipment to produce synthetic polymers. The most commonly used synthetic polymers are as follows: low density and high density polyethylenes, polyvinyl chloride, polystyrene, nylon, Teflon, etc.
Buna-S, also known as styrene – butadiene is a synthetic polymer. It is formed from the combination of butadiene and styrene. It is basically made to replace the rubbers, it has all the properties related to natural rubber and competes it in many sectors. Buna-S have good abrasion resistance and also aging stability which makes it more suitable to use.
PVC, also known as polyvinyl chloride is a synthetic plastic polymer. It comes under the category of plastics. It is made up from the vinyl chloride monomers, which are combined together in the form of a chain. It is mostly used in the manufacture of pipes, windows, wire insulations, medical devices etc.
Proteins are the natural polymers. Proteins are made out of amino acids hence proteins are polyamides so we can say that proteins are obtained from the plants and animals directly.
From the above discussions we can conclude that Proteins are the natural polymers while Buna-S and PVC are synthetic polymers.

Note:
Proteins are nothing but the long repeating chains of the molecules. The properties of these polymers depend upon the monomer units. Different varieties of polymer are seen such as heat resistant polymers, stretching polymers like rubber etc.