Plastiku

Plastics are a broad class of synthetic or semi-synthetic polymer materials that can be molded or shaped and retain their form. They are primarily made from polymers derived from petrochemical feedstocks, but some are bio-based or designed to be biodegradable. They exhibit a wide range of properties, from flexible films to rigid engineering resins.

The development of plastics began in the late 19th and early 20th centuries, with early polymers such as Bakelite. Today, plastics are categorized into thermoplastics, which soften when heated and can be remolded, and thermosets, which cure irreversibly. Elastomers provide elastic properties. Many plastics are blends or composites to tailor performance.

Common plastics include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and polyethylene terephthalate (PET). Engineering plastics such as acrylonitrile butadiene styrene (ABS), polycarbonate (PC), and polyamide (nylon) are used in more demanding applications. Packaging, construction, automotive, electronics, and consumer goods rely on plastics for weight, cost, and versatility.

Plastics are produced by polymerization, often of hydrocarbon monomers, through processes like extrusion, injection molding, and blow molding. Processing methods determine thickness, clarity, and strength. End-of-life options include mechanical recycling, chemical recycling, energy recovery, and, in some cases, composting for specific bio-based plastics.

Environmental concerns center on persistence and fragmentation of plastics in ecosystems, leading to microplastics. Recycling rates vary by polymer and region, and waste management infrastructure is crucial. Policies promote extended producer responsibility and a circular economy, though challenges remain in collection, sorting, and economically viable recycling.

Health and safety considerations include additives such as plasticizers, stabilizers, flame retardants, and processing aids. Some compounds, notably BPA and certain phthalates, have raised regulatory concerns about leaching into food or skin contact. Regulations and labeling aim to reduce exposure.