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.
Despite its shortcomings, polypropylene is a great material overall. It has a unique blend of qualities that aren’t found in any other material which makes it an ideal choice for many projects.