HDPE is high-density polyethylene while PP is polypropylene. Thus the key difference between HDPE and PP is that the HDPE is made with ethylene monomer whereas PP is made with propylene monomer. Polymers are macromolecules formed from a number of small molecules known as monomers.

Which is better HDPE or polypropylene?

Density is a key factor that differentiates HDPE from PP. Because HDPE has a lower density, it can be more rigid. Thanks to its lower density, though, PP, can be used when moulding parts with lower weight. Like HDPE, Polypropylene offers good chemical resistance.

What is the difference between PP and PE?

Polyethylene (PE) is tough yet light, with good resistance to impacts and abrasions. On the other hand, Polypropylene is harder and can be used for mechanical and structural applications. ... Polypropylene is stiffer and more chemical-resistant and scratch-resistant, while still being very tough.