Basic identification of polypropylene
In 1984, PP has become one of the world's five largest general-purpose plastics. The main raw material is propylene. The high-molecular-weight polymer of propylene is polypropylene.
The crystallinity of PP is related to its isotacticity. It is easy to crystallize with high isotacticity, its crystallinity is 30~70%, its crystallinity is high, its density is large, and its melt index is small. The measurement temperature of the melt index was 23 degrees, the density of the PP amorphous portion was 0.851 g/cm3, and the crystal portion was 0.935 g/cm3, and the crystal directly affected the density. PP has an average molecular weight of more than 80,000 and a melting point of 164 to 170 degrees.
PP polymerization:
The monomer of propylene is obtained by dehydration of petroleum, natural gas cracking or propanol, and then polymerization or solvent polymerization using Ziegler catalyst; that is, using titanium trichloride and molten aluminum as a composite catalyst, heptane or The gasoline is a solvent, and the polymerization is carried out at a pressure of 0.3 to 1 MPa, and the temperature is fed at 60 to 80 degrees to the separation and separation tank. The propylene of the reaction is discharged from the kettle, and is compressed and recycled, and the PP suspension is separated by a centrifuge. The solvent is removed, washed with methanol to remove the catalyst residue, washed with water, and dried to obtain PP.
PP identification:
PP is a colorless, odorless, non-toxic, white waxy granular material that looks like PE (polyethylene) but is more transparent and lighter than PE, with a specific gravity of 0.89 to 0.91. It is the lightest plastic variety, it is basically a linear, highly crystalline polymer that floats in water.
PP is easy to burn, burning after the fire, the upper end of the flame is yellow, the lower end of the blue has a small amount of black smoke, the melt stretchability is excellent. After burning, the melt drops and emits a petroleum smell.
Ungrouped,High Quality Ungrouped,Ungrouped Details, CN
Shaoxing Qili Import And Export Co.,Ltd , https://www.qili-apparel.com