Polypropylene is one of the most common thermoplastics used in the world
Application of polypropylene
This material includes a wide range of plastic packaging, plastic parts for machines, its equipment, fibers, textiles, etc.
It is a type of rigid thermoplastic that was polymerized in 1951 and is currently widely used in industry and home appliances.
The global demand for this thermoplastic is about 45 tons and is increasing exponentially.
Uses of polypropylene
* For use in plastic packaging
* Plastic furniture
* Gears in machines and vehicles
* Cleaning, bleaching and first aid products.
Polypropylene has served the medical world a lot due to its waterproof properties, flexibility, resistance to bacteria, mold, chemical corrosion, etc.
From the medical uses of polypropylene: (medical applications)
Syringes
Medical vials
Sample bottles
Tablet containers
Due to the different changes of propylene, this material is known as steel in the plastic industry.
Advantages of PP:
Chemical resistance: many chemicals do not react with polypropylene. In fact, it means that it is suitable for plastic containers and pallets.
Biological resistance: This plastic does not rot.
Water resistance: This material is very impermeable to water. This is a unique and essential feature for industrial applications, It is medical.
Fatigue resistance: Polypropylene maintains its shape after twisting or bending. That is why the lid of the shampoo is made of plastic.
Insulation: This plastic is very resistant to electricity and this feature has made it chosen for electronic components.
High melting point: One of the great features of this material that makes it suitable for kitchen utensils and food items is the high melting point of this material.
Affordable: Polypropylene is a very affordable material and is easily available to everyone.
Recyclability: This material is completely stable, so it is completely recyclable. This plastic, unlike other plastics, is used frequently.
Food containers are often made from polypropylene
Disadvantages of polypropylene:
• Flammable: polypropylene burns easily, but there are other grades that are more resistant to flame.
• Degradation due to ultraviolet rays: this material is prone to damage from sunlight, and this causes the destruction of its polymer bonds. Therefore, in its pure form, it is not a suitable choice for exposure to the sun. Of course, this feature can be slightly improved by using pigments and other additives.
• Limitation at high temperature: This plastic can withstand some heat, but it will start to deform at high temperatures because it has a high expansion coefficient.
• It has little resistance to chlorinated solvents and aromatic substances
• Sensitive to oxidation: This material is sensitive to oxidative thermal degradation, which can be partially solved by adding antioxidants.
Mechanical properties of polypropylene:
Polypropylene always aces the tensile test. (Source: Instron)
A few questions about polypropylene
The difference between polypropylene PP and HDPE
As we mentioned in previous blogs, HDPE is a type of high-density polyethylene, while PP is polypropylene. That is, their structural difference is due to the fact that HDPE is made with ethylene monomers, but PP is combined with polypropylene monomers.
Definition of polymer: Polymers are large molecules that consist of a number of smaller subsets called monomer molecules.
Is the material of the bottle cap HDPE or PP?
In general, bottle caps are made of high density polyethylene (HDPE) and polypropylene (PP). In terms of demand, both of them have many applications in the markets.
But HDPE is a type of high-density plastic that is very rigid. It has high resistance to heat and water vapor. (heat resistance).
It also protects the contents inside the package well from damage.