- For the heat resistance point of view, polypropylene heat resistance is higher than polyethylene. Polypropylene melting temperature is about 40%-50% higher than polyethylene, about 160-170℃, so the products can be sterilized at more than 100℃, without external force. PP rope 150℃ is not deformed. Polypropylene is characterized by low density, superior mechanical properties to polyethylene and outstanding rigidity.
- For the perspective of low temperature resistance analysis, low temperature resistance of polypropylene is weaker than polyethylene, 0℃ impact strength is only half of 20℃, and polyethylene brittle temperature can generally reach -50℃ below; With the increase of relative molecular weight, the minimum can reach -140℃. Therefore, if the products need to be used in low temperature environment, or as far as possible to choose polyethylene as a raw material.
- For the perspective of aging resistance, the aging resistance of polypropylene is weaker than that of polyethylene. Polypropylene has a similar structure to polyethylene, but because it has a side chain composed of methyl, it is easier to be oxidized and degraded under the action of ULTRAVIOLET light and heat energy. The most common polypropylene products that are easy to age in daily life are woven bags, which are easy to break when exposed to the sun for a long time.In fact, polyethylene aging resistance is higher than polypropylene, but compared with other raw materials, its performance is not very outstanding, because there is a small number of double bonds and ether bonds in polyethylene molecules, its weather resistance is not good, sun, rain will also cause aging.
- For the perspective of flexibility, although polypropylene has high strength, its flexibility is poor, which is also poor impact resistance from a technical point of view.
Post time: Feb-28-2022