polivinil

Polivinil, often rendered as polyvinyl in English, is a general term for polymers derived from vinyl monomers (ethenyl compounds). These materials are formed by addition polymerization of vinyl units, yielding long chains with repeating -CH2-CH(R)- segments where R represents various substituents. The class encompasses a range of polymers whose properties and uses vary widely depending on the monomer and processing.

The most well-known polyvinyl polymers include polyvinyl chloride (PVC), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), and polyvinylidene fluoride (PVDF). PVC is widely used in pipes, window frames, cables, and flooring due to its chemical resistance and rigidity, with plasticizers added to increase flexibility. PVAc find use as adhesives and coatings, while PVA is notable for its water-soluble films and fibers. PVDF offers high chemical and thermal resistance for coatings and membranes. Other vinyl polymers include polymethyl vinyl ether, polyvinyl formal, and various copolymers.

Production typically relies on radical polymerization of vinyl monomers, carried out in bulk, solution, suspension, or emulsion. Initiators such as peroxides or azo compounds drive chain growth, and polymer properties are tuned by molecular weight, comonomers, and processing conditions. Techniques like emulsion polymerization are common for PVC, producing fine latexes used in coatings and binders.

Environmental and safety considerations vary by polymer. PVC, for example, contains chlorine and additives that raise recycling and combustion concerns. Recycling streams, disposal, and potential health or environmental impacts of additives (such as plasticizers) are active areas of regulation and research. Overall, polivinil polymers form a diverse family with broad industrial applications and ongoing attention to sustainability.