What is Poly Propylene (PP) ?
Polypropylene (PP) is a thermoplastic “addition polymer” made from a combination of propylene monomers. It is used in a variety of applications including packaging for consumer products, plastic parts for various industries including the automotive industry, special devices like living hinges, and textiles.
What are the Characteristics of Polypropylene?
There are two main types of polypropylene available: homopolymers and copolymers. The copolymers are further divided into block copolymers and random copolymers.
Each category fits certain applications better than the others. Polypropylene is often called the “steel” of the plastic industry because of the various ways in which it can be modified or customized to best serve a particular purpose.
This is usually achieved by introducing special additives to it or by manufacturing it in a very particular way. This adaptability is a vital property.
Homopolymer polypropylene is a general-purpose grade. You can think of this like the default state of the polypropylene material. Block copolymer polypropylene has co-monomer units arranged in blocks (that is, in a regular pattern) and contain anywhere between 5% to 15% ethylene.
Ethylene improves certain properties, like impact resistance while other additives enhance other properties.
Random copolymer polypropylene – as opposed to block copolymer polypropylene – has the co-monomer units arranged in irregular or random patterns along the polypropylene molecule.
They are usually incorporated with anywhere between 1% to 7% ethylene and are selected for applications where a more malleable, clearer product is desired.
What are the Characteristics of Polypropylene?
There are two main types of polypropylene available: homopolymers and copolymers. The copolymers are further divided into block copolymers and random copolymers.
Each category fits certain applications better than the others. Polypropylene is often called the “steel” of the plastic industry because of the various ways in which it can be modified or customized to best serve a particular purpose.
This is usually achieved by introducing special additives to it or by manufacturing it in a very particular way. This adaptability is a vital property.
Homopolymer polypropylene is a general-purpose grade. You can think of this like the default state of the polypropylene material. Block copolymer polypropylene has co-monomer units arranged in blocks (that is, in a regular pattern) and contain anywhere between 5% to 15% ethylene.
Ethylene improves certain properties, like impact resistance while other additives enhance other properties.
Random copolymer polypropylene – as opposed to block copolymer polypropylene – has the co-monomer units arranged in irregular or random patterns along the polypropylene molecule.
They are usually incorporated with anywhere between 1% to 7% ethylene and are selected for applications where a more malleable, clearer product is desired.
What are the Advantages of Polypropylene?
- Polypropylene is readily available and relatively inexpensive.
- Polypropylene has high flexural strength due to its semi-crystalline nature.
- Polypropylene has a relatively slippery surface.
- Polypropylene is very resistant to absorbing moisture
- Polypropylene has good chemical resistance over a wide range of bases and acids.
- Polypropylene possesses good fatigue resistance.
- Polypropylene has good impact strength.
Polypropylene is a good electrical insulator.
What are the Disadvantages of Polypropylene?
- Polypropylene has a high thermal expansion coefficient which limits its high temperature applications.
- Polypropylene is susceptible to UV degradation.
- Polypropylene has poor resistance to chlorinated solvents and aromatics.
- Polypropylene is known to be difficult to paint as it has poor bonding properties.
- Polypropylene is highly flammable.
- Polypropylene is susceptible to oxidation.