Question

Which of the following is a natural polymer? Buna-S, Proteins, PVC

Answer 1

Polymer is a compound that is formed by a combination of monomers. If different monomers are combined to form a polymer then it is called a copolymer. And if the same monomers are joined to form a polymer then it is called a homopolymer.

Complete step by step answer:
Natural polymers are obtained naturally. And there are some polymers which are man-made. They are known as synthetic polymers.
Proteins are natural polymers. Which are made of amino acids by animals, fungi, plants etc. on the other hand Buna -S and PVC are man-made synthetic polymers.

Additional information:
Synthetic fibers are man-made fibers, that are prepared from raw material petroleum known as petrochemicals. All fabrics are generally obtained from fibers, while fibers are obtained from man-made sources. They consist of a small unit or a polymeric chain which is made from many repeating units called monomers. For example, nylon, acrylics, polyurethane, and polypropylene.
The material of synthetic fiber is thermoplastic in nature. Thermoplastic materials are those polymers that can be easily melted and molded indefinitely on heating and harden upon cooling. When frozen, they become glass-like and can be broken. Due to its this property, clothes made from synthetic fibers become hazardous and dangerous if brought near fire. For example, PVC, Bakelite etc.
Thermosetting plastics are a class of plastics that cannot be reshaped into another form factor after it is formed. To put it in simpler terms, thermosetting plastics are those plastics that become irreversibly fixed in a particular shape and just lose all their properties if they are tried to be reheated.

Note:
Bakelite was the first plastic made from synthetic components. It is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde. The monomer of PVC is vinyl chloride.