Theory:

Everything we use in modern life is of polymer-based from tv, bags, mobiles, bikes etc. These synthetic polymers are widely used in our daily life. These are also risk to environment as they are non-bio degradable in nature.
The artificially prepared or human-made polymers are called as synthetic polymers. The monomer is the repeating unit in the polymer. These are long-chain molecules. 
Synthetic polymers are prepared from raw materials such as petroleum oil and gas. Propylene and ethylene monomers are removed as byproducts during the production of petrol. 
  
The structure of propylene is as shown below in this image.
shutterstock_1750599650_new.jpg
  
Types of synthetic polymers:

We can prepare synthetic polymers of different types based on our need and uses. Commonly used polymers are of organic (having the building block as hydrocarbon) based. Some of the synthetic polymers are low density polyethylene (LDPE), polypropylene, polyvinyl chloride (PVC), nylon, Teflon, high density poly ethylene (HDPE), etc.

shutterstock_393221374.jpg

The above image is use of nylon as wires or ropes.

pan-544679_1280.jpg

The above image is the use of Teflon in making non-stick pans.

the-bottle-5128607_1280.jpg

The above image is the use of PET in making plastic bottles.

We nylon is used in making dresses, wires, and Teflon is used in non-stick cookery items, polyethylene terephthalate (PET) is used in making plastic bottles etc. Let us now see LDPE and PVC synthetic polymers in brief.

Low density polyethylene (LDPE):  
The monomer is ethylene which is the building block for low-density polyethylene.
This is a thermoplastic polymer which means they are recyclable polymers. They have the property to soften when heated and have weak intermolecular forces between the polymer chains.
 
shutterstock_715352785_new.jpg
 
The best advantage of LDPE is that they have good electrical insulation and are waterproof. The main disadvantage is that they are prone to cracks.
 
shutterstock_1717937152.jpg
Plastic bags
  
The application of LDPE is that they are used in making plastic bags, toys, pipe, wire and cable insulations, utensils etc.
  
Poly vinyl chloride (PVC):
 
The monomer is vinyl chloride (chloroethylene) which makes in this polymer. This is the thermoplastic polymer and rigid in nature.
 
shutterstock_318765347_new.jpg
 
The advantage of PVC is they are inexpensive and are good insulators. The disadvantage of PVC is that they have very poor heat stability.
 
shutterstock_536475100.jpg
PVC pipes
 
The application of PVC is that they are used for pipes, window frames and roofing, waterproof linings, waterproof clothing, life-jackets, inflatables and sporting goods etc.