Which material is better, PET or PP?

Compared with PET and PP materials, PP will be more superior in performance.
1. The difference from the definition
PET (Polyethylene terephthalate) scientific name is polyethylene terephthalate, commonly known as polyester resin, is a resin material.
PP (polypropylene) scientific name is polypropylene, which is a polymer formed by addition polymerization of propylene, and is a thermoplastic synthetic resin.
2.From the characteristics of the difference
(1) PET
①PET is a milky white or light yellow highly crystalline polymer with a smooth and shiny surface.
②PET material has good fatigue resistance, abrasion resistance and dimensional stability, low wear and high hardness, bending strength of 200MPa, and elastic modulus of 4000MPa.
③The PET material has excellent high and low temperature resistance performance, which can be used for a long time in the temperature range of 120 °C, and can withstand high temperature of 150 °C for short-term use and low temperature of -70 °C.
④ Ethylene glycol used in the production of PET has low cost and high cost performance.
⑤The PET material is non-toxic, has good stability against chemicals, and is resistant to weak acids and organic solvents, but it is not resistant to immersion in hot water and alkali.
(2) PP
①PP is a white waxy material with a transparent and light appearance. It is the lightest kind of commonly used resins.
②PP material has excellent mechanical properties and good heat resistance, and the continuous use temperature can reach 110-120 °C.
③PP material has excellent chemical stability and does not interact with most chemicals except for strong oxidants.
④PP material has higher melting temperature and tensile strength, and the transparency of the film is higher.
⑤PP material has excellent electrical insulation, but it is easy to age and has poor impact strength at low temperature.
3. Differences in use
PET is widely used, such as spinning into polyester fiber, that is, polyester; as plastic, it can be blown into various bottles; as electrical parts, bearings, gears, etc.
PP material is widely used in the production of injection molding products, films, pipes, plates, fibers, coatings, etc., as well as household appliances, steam, chemical, construction, light industry and other fields.