Polypropylene is economical and offers an excellent combination of physical, chemical, mechanical, thermal, and electrical properties that are not found in any other thermoplastic. Though lower in impact strength than polyethylene, PP has superior working temperature and tensile strength.

PP possesses excellent resistance to organic solvents, degreasing agents, and electrolytic attack. It is light-weight, stain-resistant, with low moisture absorption rate. Being a tough, heat-resistant, and semi-rigid material, it is ideally suited for the transfer of hot liquids or gases. It has excellent resistance to acids and alkalis too.

There are three general types of PP: Homopolymer, Random Copolymer, and Block Copolymer. The co-monomer used is typically ethylene. Ethylene-propylene rubber or EPDM added to PP homopolymer increases its low temperature impact strength. Randomly polymerized ethylene monomer added to PP homopolymer decreases the polymer crystallinity and makes the polymer more transparent.

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