page_title: Polypropylene
section_title: Chemical and physical properties
hierarchical_section_title: Polypropylene / Chemical and physical properties
caption_attribution_description: English: Micro graph of polypropylene with a light microscope. Semi-crystalline polymer, visible spherulite structures.
context_page_description: Polypropylene, also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene.
  Polypropylene belongs to the group of polyolefins and is partially crystalline and non-polar. Its properties are similar to polyethylene, but it is slightly harder and more heat resistant. It is a white, mechanically rugged material and has a high chemical resistance. Polypropylene is the second-most widely produced commodity plastic and it is often used in packaging and labeling. In 2019, the global market for polypropylene was worth $126.03 billion.
context_section_description: Polypropylene is in many aspects similar to polyethylene, especially in solution behaviour and electrical properties. The methyl group improves mechanical properties and thermal resistance, although the chemical resistance decreases. The properties of polypropylene depend on the molecular weight and molecular weight distribution, crystallinity, type and proportion of comonomer (if used) and the isotacticity. In isotactic polypropylene, for example, the methyl groups are oriented on one side of the carbon backbone. This arrangement creates a greater degree of crystallinity and results in a stiffer material that is more resistant to creep than both atactic polypropylene and polyethylene.
caption: Micrograph of polypropylene
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