polimerens

Polimerens are large molecules composed of repeating subunits called monomers. They can be linear, branched, or crosslinked, and their properties depend on molecular weight, composition, chain architecture, and stereochemistry. They occur naturally, such as cellulose, proteins, and DNA, and synthetically produced polymers include polyethylene, polystyrene, nylon, and polyurethanes.

Polymerization joins monomers to form polymers. The main classes are addition (chain-growth) polymerization, which builds the chain by successive additions, and condensation (step-growth) polymerization, in which small molecules are released. Methods include free-radical, anionic, and cationic polymerization for addition polymers, and polycondensation for many polyesters and nylons.

A polymer’s structure—molecular weight, distribution, tacticity, crystallinity, and crosslinking—shapes its properties. Glass transition temperature (Tg) and melting temperature (Tm) mark thermal transitions; properties range from rigid to highly elastic. Solubility, chemical resistance, and environmental stability are also important.

Applications span packaging, textiles, automotive parts, electronics, and medical devices. Notable examples include polyethylene, polypropylene, polystyrene, PET, PVC, nylon, and polyurethane. Natural polymers such as cellulose and proteins underpin biological structures.

Environmental aspects include recycling, disposal, and biodegradation considerations. Design trends emphasize sustainable and bio-based polymers and circular economy approaches to reduce waste. The study of polymers emerged in the early 20th century with work by Hermann Staudinger and was advanced by Wallace Carothers.