Polypropylene has high crystallinity and regular structure, so it has excellent mechanical properties. The absolute value of the mechanical properties of polypropylene is higher than that of polyethylene, but it is still a low variety among plastic materials, and its tensile strength can only reach 30 MPa or a slightly higher level. Polypropylene with a larger isotactic index has higher stretch.

Polypropylene is a non-toxic, odorless and tasteless milky white highly crystalline polymer with a density of only 0.90–“0.91g/rm. It is one of the lightest varieties of all plastics. It is particularly stable to water. The water absorption rate in water is only 0.01%, and the molecular weight is about 80,000 to 150,000. The moldability is good, but due to the large shrinkage rate (1%~2.5%)。