Polymermaterial

Polymer material, or polymer, is a substance made of long chains of repeating units called monomers. Polymers can be natural (cellulose, proteins) or synthetic (polyethylene, polyvinyl chloride). Their properties depend on molecular weight, chain architecture, and crystallinity.

Polymers are commonly categorized by thermomechanical behavior as thermoplastics, thermosets, and elastomers. Thermoplastics soften with heat and can be remolded; thermosets form crosslinked networks and do not melt; elastomers exhibit high elasticity. Chain structure varies from linear to branched or crosslinked, with varying crystallinity and tacticity affecting properties.

Most polymers are produced by polymerization, either addition (chain-growth) or condensation (step-growth). Shaping methods include extrusion, injection molding, blow molding, film casting, electrospinning, and additive manufacturing. Fillers, plasticizers, and stabilizers are common additives.

Key properties include strength-to-weight, chemical and weather resistance, and electrical insulation. Thermal properties such as glass transition temperature and melting point, along with mechanical properties like modulus and toughness, depend on composition and processing.

Applications span packaging, automotive, construction, electronics, and medical devices. Common examples are polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylon, polyurethane, epoxy resins, and polycarbonate.

Environmental considerations include recyclability and lifecycle impacts. Biobased and biodegradable polymers exist, but disposal, recycling infrastructure, and microplastic concerns influence material choice and policy.