Polypropylene (PP) is a thermoplastic polymer that is obtained through the polymerization of propylene. It is one of the plastics of the group of polyolefins (it is obtained by the polymerization of olefins). It is one of the plastics that are most used. It can be used as a plastic or as a fiber, that is why it has several applications: textiles, medical devices, automotive components… Propylene has good mechanical and chemical resistance, is resistant to water, is of low density (0.895-0.92 g / cm³) and has a melt of from 160ºC. It is a partially crystalline material. Being rigid, it is a difficult material to deform even with impacts. At low temperatures, it is a material that becomes more brittle. There are 2 types of polypropylene: PP Homopolymer - created by polymerizing pure propylene. There are three types: - Isotactic PP: has great crystallinity, mechanical resistance and toughness. - Atactic PP: polymerizes leaving the side methyls especially in disorder. It is a sticky material so it sticks well to surfaces. - Syndiotactic PP: it has little crystallinity, it is more elastic than isotactic but less resistant. Copolymer PP: achieved when 5-30% ethylene is added in polymerization. It has more resistance to impact than homopolymer. There are 2 types: - Random copolymer: propylene and ethylene are put into the same reactor at the same time, thus creating polymer chains in which the two take turns randomly - Block copolymer: first the propylene is polymerized in a reactor and then ethylene is added in another once the PP has been formed. Their resistance is very high, that is why they are also called PP impact / shock. Polypropylene is recyclable and its identification number is 5. PP waste can come in the form of industrial scrap or in the form of post-consumer waste. It is 99% carbon and hydrogen so it is not chemically polluting. As it has energy almost as fossil fuels do, many PP residues are used as an alternative to use it as a fuel to produce electrical energy and heat. The most widely used methods for recycling PP are extrusion, injection and mechanical recycling.
We use our own and third-party cookies to obtain statistical data on our users' browsing habits and improve our services.