Polypropylene is a thermoplastic resin prepared by polymerization of propylene. According to the position of methyl groups are divided into isotactic polypropylene, atactic polypropylene and intertactic polypropylene.
Polypropylene is a non-toxic, odourless, tasteless and opalescent polymer with high crystallinity. It is currently one of the lightest varieties of all plastics. It is particularly stable to water, water absorption rate is only 0. 01%, molecular weight is about 81 thousand 150 thousand. Good formability,
Non-toxic, tasteless, small density, strength, stiffness, hardness and heat resistance are better than low-pressure polyethylene, can be used at about 100ºC. It has good dielectric properties and high frequency insulation and is not affected by humidity, but it becomes brittle at low temperature and is not wear-resistant and easy to aging. Suitable for making general mechanical parts, corrosion-resistant parts and insulating parts. Common acid, alkali and other organic solvents almost have no effect on it, can be used for food.
Polypropylene has many excellent properties:
1, the relative density is small, only 0.89-0.91, is one of the lightest varieties of plastic.
2, good mechanical properties, in addition to impact resistance, other mechanical properties are better than polyethylene, good molding performance.
3, with high heat resistance, continuous use temperature up to 110-120ºC.
4, good chemical properties, almost no water, and the vast majority of chemicals do not react.
5, pure texture, non-toxic.
6, good electrical insulation.
7. The transparency of polypropylene products is better than that of high-density polyethylene products.