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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