The name of this product is polypropylene (PP) and its chemical formula is -[CH2-CH(CH3)]n-.
Polypropylene is one of the most widely used and basic polymers used in the world and It is the largest consumer of propylene.
It was first produced on a laboratory scale in the early 1950s and then reached commercial production at the end of this decade. From the beginning, it was estimated that the production cost of polypropylene PP is lower than polyethylene PE.
Polypropylene PP is produced in three forms, isotactic, syndiotactic, and atactic, which is mainly in the isotactic form and with the addition of a small amount of other monomers. (mostly polyethylene PE).
Polypropylene is made from the polymerization of propylene under relatively mild temperature and pressure conditions and in the presence of the famous Ziegler-Natta catalyst.
The existence of this catalyst, a polymer It forms an isotactic form which is able to crystallize up to 90%.
Polypropylene is one of the most widely used plastics and is widely used in various industries today.
Polypropylene is a thermoplastic polymer that is used in a wide range of applications including film and sheet, blow molding, injection molding, food packaging, textile, laboratory and medical equipment, pipe, industrial and construction applications, and automotive components. In addition, the polymer produced from propylene monomer is usually resistant to chemical solvents, bases and acids. The characteristic code of this polymer is.
The propylene molecule has an asymmetric chemical structure, hence its polymerization process can lead to three types of sequences in the structure of the resulting polymer. Due to the effects caused by the steric hindrance of methyl groups, the head-to-tail sequence has a higher structural order than other types. It has provided in the plastic and fiber industry. One of the most important characteristics of this material compared to polymers such as polyamides is the lack of moisture absorption in it, which has made it a suitable option for many applications. Some later amendments improved. The most important reforms that are currently being carried out are the control of the destruction process, networking, agentization and branching. The structure of the polypropylene molecule is linear due to the nature of the Ziegler-Natta catalysts, which causes its melt strength to be low. The low melt strength limits the use of this polymer in processes such as blow molding and thermoforming.
Compared to other polymers, polypropylene has distinct and outstanding characteristics, which include:
- Relatively cheap price of propylene monomer compared to monomers of other polymers
- Low price of PP compared to other polymers
- Specific weight and lightness of PP
- Flexibility and wide range of PP production with variable physical and chemical properties
- increasing new applications and improving the properties of new production grades
- increasing the use of PP in medical devices and equipment and developing special grade PP applications
- increasing the use of PP as an alloy with other polymers
- Replacing polymers such as PS, PE, etc. with
Attributes
Tensile resistance, low density, colorless, hardness, resistance to acid, base and solvents are among the characteristics of polypropylene PP. Its low production cost compared to other thermoplastics has created a special place for polypropylene PP in the industry.