Question

Which of the following are polyester polymers?
A. Bakelite
B. Dacron
C. Glyptal resins
D. Nylon-5

Answer 1

Hint: For this problem we will basically look at what are the polyester polymers. Also, what kind of polymers come under this category. Polyester comes in the type of synthetic polymers having various uses in clothing and many other things.

Complete step by step answer: First of all, what are polymers. Polymers define the materials made up of long and repeating chains of molecules. You can understand it as ‘POLY’ meaning ‘many ‘and ‘MER’ meaning repeating unit.
There are natural polymers like silk, hair, proteins and man-made polymers like polyethylene, polyester, and many others.
Now comes to polyester polymers, basically polyester is a category of polymers that contain the ester functional group in their main chains. These are the condensation polymers of diacids and diols.
Thermoplastic polymers are the ones which become soft when heated and hard when cooled. Polyesters are a common example.
Thermosetting polymers is a polymer that becomes hard on heating. Bakelite is an example to these types of polymers.
Bakelite is a thermosetting polymer. It is used for making electrical switches, handles of various utensils. Bakelite is made up of monomers phenol and formaldehyde. Phenol-formaldehyde resin is a thermosetting polymer.
Dacron, it is also known as terylene. It is a polymer formed from polymerization of ethylene glycol (ethane-1,2-diol) and terephthalic acid (benzene-1,4-dicarboxylic acid). Due to its much durability and resistance towards creases it is used in making wash and wear fabrics and also seat belts, tyre cords. Dacron is one of the important examples of polyester polymers.
Glyptal resins, the name glyptal refers to polymers that are synthesised by condensation of dibasic acids or their anhydrides and polyhydric alcohols like glycol or glycerol. It is also an important example of polyester polymers. One of the simplest glyptal is synthesised from the condensation of ethylene glycol and phthalic acid.
Nylons are basically polyamides. It is a thermoplastic material that can be used into fibres.
As explained above, Dacron and glyptal resins are polyester polymers.

So, the correct answers are “Option B & C”.

Note: The monomers of every polymer should be kept in mind. Moreover, the above two polyester polymers are the most important and frequently asked examples. It is made of purified terephthalic acid or its dimethyl ester.