Difference Between Polypropylene and Polyethylene

Main difference

The main difference between polypropylene and polyethylene is that polypropylene is the monomer of propylene while polyethylene is a monomer of ethylene…

Polypropylene vs Polyethylene

Polypropylene and polyethylene are thermoplastic polymers. Both polymers are widely used in a wide range of industrial and domestic applications. Polypropylene is made from a combination of propylene monomers while polyethylene is made from a combination of polyethylene monomers. Polypropylene is highly modifiable, adaptable and moldable, while polyethylene is very resistant and not easily malleable. Polypropylene is abbreviated as PP and polypropylene is known as PE. Polypropylene is known for its conformability and ability to be molded by heat, while propylene is known for its ability to withstand cold temperatures. Polypropylene is not as stable as polyethylene. Polypropylene has a higher static charge than polyethylene. Polypropylene can only be modified translucent and polyethylene can always be made optically clear. Polypropylene is a poor insulator while polyethylene is a good electrical insulator. PP has a higher melting point and lower cost than PE. PP weighs lighter than PE. Polypropene is also more resistant to organic and chemical solvents than polyethylene. PP can be made into fibers, but PE cannot be made into fibers. Both also have different chemical formulas. PP weighs lighter than PE. Polypropene is also more resistant to organic and chemical solvents than polyethylene. PP can be made into fibers, but PE cannot be made into fibers. Both also have different chemical formulas. PP weighs lighter than PE. Polypropene is also more resistant to organic and chemical solvents than polyethylene. PP can be made into fibers, but PE cannot be made into fibers. Both also have different chemical formulas.

Comparison chart

Polypropylene Polyethylene
propylene monomer ethylene monomer
Chemical properties
semi-crystalline inert, translucent
electrical properties
high static load
poor insulator
low static load
good insulator
Melting point
130 to 171 °C (266 to 340 °F; 403 to 444 K) 115–135 °C (239–275 °F; 388–408 K)
Chemical formula
C3H6 ) n _ _ ( C2H4 ) _
Fibers, films, covers, hinges, synthetic paper and for the production of various chemical products such as acrylonitrile, acrylic acid, propylene oxide, cumene and butyraldehyde. Plastic bags, bottles, food containers, pallets, geomembranes, plastic films, food boxes, etc.
0.855 g/ cm3 amorphous, 0.946 g/ cm3 crystalline 0.88–0.96 g/ cm3
J. Paul Hogan and Robert Banks (1951) and Giulio Natta, Karl Rehn (1954). Hans von Pechman (1898).
Alternative Names
Polypropylene Polyethylene
Cheap Expensive
What is polypropylene?

A polymer, polypropylene is also known as polypropylene. PP is abbreviated. And it has a chemical designation of (C 3 H 6 ) n.It is a thermoplastic polymer but it can also be adapted to different manufacturing procedures. It is produced primarily from a propylene monomer by the process called chain growth polymerization. It is a versatile plastic product, which also functions as a fiber. In 1954, it was first polymerized by an Italian chemist and Professor Giulio Natta, but originally created by the German Karl Rehn. Polypropylene’s ability to semi-crystallize created quite a stir and became very popular in commercial production throughout Europe in 1957. Polypropylene has a unique ability. It can be manufactured through various methods and used in many applications such as packaging, injection molding, and fiber. This plastic product is the second most popular in the world, preceded by polyethylene, which ranks first. Propylene is of two types, namely homopolymers and copolymers. It is highly modifiable and moldable, and its properties make it a very resourceful material for many industries, especially the plastics industry. The adaptability of polypropene is a vital property. Compared with other plastics, this one has a higher melting point but the same weight as them. It has elasticity without softness and is very economical. It is resistant to chemicals such as acids and water-based bases. This also maintains its original shape even after being flexed or bent, so it has a resistance to fatigue. Other than that, polypropylene is very useful for electronics components due to its electrically resistant nature. It is very valuable in the manufacture of fibers, carpets, ropes, clothing and upholstery, and is mainly used by the packaging industry. The automotive industry and household appliances also consume ten percent of this thermoplastic. Toys, household clothes also use it. However, it is not heat resistant, is highly flammable, and tends to warp easily in the heat.

What is polyethylene?

Polyethylene or polyethylene is also a polymer, but it is made from an ethylene monomer. It has a chemical formula of (C 2 H 4 ) n. The first synthesis of this occurred as an accident in 1898 by the German scientist Hans von Pechmann. Like PP, it is also a thermoplastic by its very nature. Its abbreviated form is PE. PE ranks first as the most widely used plastic in the world. However, not all plastics are PE. Polyethylene is not easily malleable because it is very stable. It is a good electrical insulator. It has a very low melting point and is widely used in the automotive industry as well as in the food packaging industry. Approximately 70 percent is used in food packaging, food containers, pallets, and even boxes and bottles.


  • Ultra High Molecular Weight Polyethylene (UHMWPE)
  • Ultra Low Molecular Weight Polyethylene (ULMWPE or PE-WAX)
  • High Molecular Weight Polyethylene (HMWPE)
  • High density polyethylene (HDPE)
  • High Density Cross-linked Polyethylene (HDXLPE)
  • Cross-linked polyethylene (PEX or XLPE)
  • Medium Density Polyethylene (MDPE)
  • Linear Low Density Polyethylene (LLDPE)
  • Low density polyethylene (LDPE)
  • Very Low Density Polyethylene (VLDPE)
  • Chlorinated polyethylene (CPE)

Key differences

  1. Polypropylene is abbreviated as PP and polyethylene is commonly known as PE.
  2. Polypropylene is the second most used plastic product in the world and polyethylene is the first.
  3. PP is very cheap and PE is very expensive.
  4. Polypropene has a higher melting point than polyethylene.
  5. Polypropylene is less resistant than polyethylene.
  6. Polypropylene has less weight than PE.
  7. Polypropene is a poor electrical insulator compared to polyethylene.
  8. Polypropylene is made from a mixture of propylene monomers and polyethylene is made from a mixture of ethylene monomers.
  9. Polypropylene is mainly used in the automobile and packaging industries, hinges, electrical appliances and toys, carpets, fibers, covers, synthetic papers, etc., and polyethylene is used in plastic bags, food containers and bottles, films, food boxes and pallets, etc.
  10. Polypropylene has the chemical formula (C 3 H 6 ) n and polyethylene is (C 2 H 4 )
Final Thoughts

However, although polypropylene and polyethylene share some physical properties, they are totally different in nature and the way they are used. PP is more flexible and PE has more resistance. PP is also elastic in nature, but PE is stable. They are also made from the polymerization of different monomers such as propylene and ethylene. But both are equally important plastic products in the world.

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