What is polypropylene?
Polypropylene is a thermoplastic resin consisting mainly of propylene monomers. Polypropylene is a thermoplastic that can have both amorphous and crystalline properties.
Amorphous polypropylene is disordered and has no crystalline structure. It has lower stiffness and hardness than crystalline polypropylene, but is more malleable and has higher impact strength. Amorphous polypropylene is often used in flexible applications such as packaging and textiles.
Crystalline polypropylene has a regular, three-dimensional crystalline structure. It has higher stiffness and hardness than amorphous polypropylene and is more suitable for applications that have to withstand high loads. Most commercially available types of polypropylene are semi – or semi-crystalline, i.e. they consist of an amorphous and a crystalline portion. Semi-crystalline polypropylene is commonly used in applications such as automotive parts and household items.
It is a lightweight, strong and durable material that is resistant to moisture and chemicals. It also has good heat resistance and can be made in a variety of colours and shapes. Another advantage of polypropylene is its recyclability, which makes it an environmentally friendly choice for many applications.
Polypropylene can be reinforced with glass fibre or carbon fibre. These combinations are called composites because they combine the advantages of polypropylene with those of glass fibre or carbon.
In a composite with glass fibre, polypropylene is used as a matrix to transfer the forces between the fibres. These composites are often used in applications such as automotive components, sports equipment and building materials.
In a carbon fibre composite, polypropylene is used as a matrix to transfer the forces between the fibres. These carbon fibre – composites are commonly used in applications such as building aerospace structures, building racing cars and building high performance components for the oil and gas industry.
Polypropylene composites used in automotive, aerospace and other high performance applications are semi-crystalline because they have higher stiffness and hardness.
Some examples of polypropylene in a matrix with glass fibre or carbon fibre are:
Automotive parts: Polypropylene is often used in conjunction with glass fibres to make components such as bumpers, bonnets and door panels. These components are lightweight, strong and durable and help to reduce the weight of the vehicle and improve fuel efficiency.
Sports equipment: Polypropylene combined with fibreglass is often used in sports equipment such as skis, snowboards and tennis rackets. This equipment is lightweight, strong and durable and enables athletes to improve their performance.
Demand for polypropylene composites is expected to continue to grow in the coming years, especially in applications that require lightweighting, high performance and durability.
Some of the key drivers for the future of polypropylene composites are:
Environmental friendliness: polypropylene composites are lightweight and allow products to be lighter, contributing to reduced CO2 emissions and improved fuel efficiency.
High performance: Polypropylene composites combine the advantages of polypropylene with those of glass fibres or carbon fibres, making it possible to produce high-performance products that are more resistant to high stresses and extreme conditions.
Cost-efficiency: Polypropylene composites are more cost-efficient than many other materials and enable the production of products that are cheaper and at the same time higher performing.
Recycling: Polypropylene has a high recycling rate and more and more technologies are being developed to enable the reuse of polypropylene composites.