Plastics are ubiquitous, ranging from food packaging and drinking bottles to the insulation in our homes. They are predominantly derived from fossil fuels like oil and natural gas. But what distinguishes one type of plastic from another? Here’s a concise guide to the most frequently used plastics and their acronyms, as categorized by the Organisation for Economic Cooperation and Development (OECD).
Thermoplastics are the most prevalent plastics due to their malleability when heated, allowing them to be remelted. In contrast, elastomers can be stretched significantly and then return to their original shape. Thermosets, on the other hand, are resins that become permanently hard when heated. Within each category, an extensive array of polymers is mixed with various additives, some of which can be detrimental to the environment or health. These additives can alter the color of plastics, prevent aging, enhance flexibility, increase impact resistance, or reduce flammability.
Polypropylene (PP) is the most widely used plastic globally, accounting for 16 percent of the market. Developed in the mid-1950s, it is utilized in automobile parts, food packaging, and disposable trays. High and low density polyethylenes each constitute 12 percent of global plastic usage, according to the OECD. HDPE, invented in 1933 by British engineers, is employed in toys, shampoo bottles, pipes, engine oil cans, and various household items. LDPE, developed in the 1950s, is commonly used to produce flexible products like reusable bags and food packaging film.
Polyvinyl chloride (PVC) is predominantly used in construction for window frames, floor coverings, pipes, and cable insulation, representing 11 percent of global plastic. Polystyrene (PS), invented in 1931 by IG Farben, accounts for five percent of the world's plastic and is primarily used for food packaging. In its unexpanded form, it is used for yogurt packaging or in construction, while expanded, it is used for fish packaging or insulation in construction. Polyethylene terephthalate (PET), also representing five percent of global plastic, is the most widely used plastic for drink bottles, both in transparent forms (water, sodas) and opaque versions for long-life milk.
Polyurethane (PUR), developed in 1937 by Otto Bayer, is used in insulation and mattresses, accounting for four percent of the world's plastic. It is mainly employed in refrigerator insulation, padding foam in buildings, adhesives, various coatings, shoe soles, and composite wood panels or surfboards. Together, these plastics represent 22 percent of all plastic and include ABS (acrylonitrile, butadiene, styrene) used for tires, PBT (polybutylene terephthalate), PC (polycarbonate), PTFE (polytetrafluoroethylene), and PMMA, another name for plexiglass. This group is derived from biomass such as corn, sugarcane, wheat, or other residues, rather than petroleum products. Their production generates fewer greenhouse gas emissions than fossil-based plastics, although their volume is increasing, it is not keeping pace with other types of plastic.
Fibers made from different polymers are used in the textile industry and represent 13 percent of all plastics globally.
