How is polypropylene produced? Propylene is obtained as a byproduct of ethylene production or as a byproduct of refinery operations.
- Polypropylene (C3H6)n is produced by the polymerization of propylene (C3H6)
- Polymerization itself involves the linking of monomer units—which are unsaturated substances—through the opening of their double bonds or their cyclic structures. This linking occurs without the separation of individual molecules, so that the centesimal composition of the polymer is the same as that of the starting monomer.
- Every polymerization process consists of three characteristic stages: the initiation reaction, the growth or chain propagation reaction, and the termination reaction. The initiation reaction activates the double bond, a necessary preliminary step for the linking of monomers in the growth reactions. The termination reaction halts the unlimited growth of the polymer chain.
- The activation of the double bond in the initiation reaction can occur through the action of light, heat, ultrasound, radical species, or acidic and basic catalysts.