1984 PP has become one of the world's top five generic plastic varieties, the main raw material for propylene, propylene, namely high molecular weight polymer is polypropylene.

Crystallinity of PP and its related isotacticity, high isotactic easy to crystallize, the degree of crystallinity of 30 to 70%, high crystallinity, density, melt index is small. Melt index measured temperature is 23 degrees, PP non-crystalline portion density of 0.851g / cm3, the crystalline portion is 0.935g / cm3, crystallinity directly affects density. PP average molecular weight above 80,000, a melting point of 164 to 170 degrees.

PP polymerization:
Propylene monomer is cracking from oil, gas or alcohol dehydration come, then Ziegler polymerization catalyst or solvent polymerization method; that is fused with titanium trichloride and aluminum-based composite catalyst, heptane or gasoline as solvent, at a pressure of 0.3 ~ 1Mpa the polymerization was carried out at 60 to 80 degrees is fed into and out of the separation vessel. The reaction is self-propylene ejection vessel, and the compressed recycled, PP suspension after centrifuging, The solvent was removed, washed with methanol to remove the catalyst residue, and then washed with water, and dried to obtain PP.

PP identification:
PP is a colorless, odorless, non-toxic granular material with white waxy appearance like PE (polyethylene), but more transparent than PE, lighter specific gravity of 0.89 to 0.91. Is the lightest plastic varieties, it is essentially linear highly crystalline polymers, floating on the water.

PP is easy to burn from the fire burning successor, flame yellow top, the bottom there is a small amount of blue smoke and melt extensibility excellent after melt dripping burning issue petroleum odor.