Polypropylene Physical And Chemical Properties

1. Odorless, tasteless and non-toxic. It is the lightest among commonly used resins;
2. Excellent mechanical properties, including tensile strength, compressive strength and hardness, outstanding rigidity and bending fatigue resistance. The movable hinge made of PP can withstand more than 7×107 times of folding and bending without damage, impact strength at low temperature Poor. The tensile strength of PP is generally 21-39 MPa; the bending strength is 42-56 MPa, the compressive strength is 39-56 MPa, the elongation at break is 200%~400%, the notched impact strength is 2.2-5 kJ/m2, and the low temperature notch Impact strength 1-2 kJ/m2. Rockwell hardness R95~105;
3. Good heat resistance, continuous use temperature can reach 110-120℃;
4. Good chemical stability. Except for strong oxidants, it does not interact with most chemicals. Solvents cannot dissolve PP at room temperature. Only some halogenated compounds, aromatic hydrocarbons and high-boiling aliphatic hydrocarbons can make it swell. It has particularly good water resistance. ;
5. Excellent electrical properties, good resistance to high-frequency electrical insulation, and good electrical insulation in humid environments;
6. Since there are many tertiary carbon atoms with methyl groups on the main chain of PP, the hydrogen on the tertiary carbon atoms is easily attacked by oxygen. Therefore, PP has poor weathering resistance and must add antioxidants or ultraviolet absorbers [16];
7. Mice were orally administered 1 to 5 times at a dose of 8g/kg, and no obvious symptoms of poisoning were caused. Rats inhaled the decomposition products of polypropylene when heated to 210-220°C 30 times for 2 hours each time, causing symptoms of eye mucosa and upper respiratory tract irritation. Like polyethylene, it is prohibited to use its recycled products to hold food.