Overview of Polypropylene (PP) including background, history, advantages, limitations and typical applications.
Background: Polypropylene (PP) was discovered in 1954 and grew a strong popularity very quickly. Because of extensive research, five main variations of Polypropylene have emerged as: homopolymers, impact (block) copolymers, random copolymers, rubber modified blends, and specialty copolymers.
PP Generics
- PP Homopolymer - PP, Unspecified - PP Copolymer - PP Impact Copolymer - PP Random Copolymer - OPP Film - PP, High Crystal - PP Alloy - PP+EPDM - Etc...
- Homopolymer - Processability, Good - Food Contact Acceptable - Stiffness, Good - Impact Resistance, Good - Copolymer - Flow, High - Impact Resistance, High - Chemically Coupled
Disadvantages of
PP
- Degraded by UV
- Flammable, but retarded grades available
- Attacked by chlorinated solvents and aromatics
- Difficult to bond
- Several metals accelerate oxidative degrading
- Low temperature impact strength is poor