plasticiser

A plasticiser is a substance added to a polymer to increase its flexibility, workability, and durability. By embedding between polymer chains, it reduces intermolecular forces and increases free volume, lowering the polymer's glass transition temperature and improving pliability and processability. Plasticisers are typically liquids or low-melting solids and are partially compatible with the host polymer.

Common plasticisers include phthalates (such as di(2-ethylhexyl) phthalate, DEHP), adipates (di(2-ethylhexyl) adipate, DEHA), and citrates (acetyl tributyl citrate, ATBC). There are also polymeric plasticisers and vegetable-based or bio-derived options. Phthalates are widely used but face regulatory restrictions due to health and environmental concerns; alternatives are increasingly adopted. The choice depends on compatibility, volatility, extractability, permanence, and cost, as well as processing temperature and finished product requirements.

Applications are dominated by vinyl polymers, especially PVC, where plasticisers enable flexible films, cables insulation, flooring, coatings, and sealants. Plastics used in adhesives, elastomers, and some packaging also employ plasticisers. The same principle applies to modifying thermoplastics and some thermosets.

Regulatory and safety aspects: some plasticisers can migrate from products and pose health risks, particularly for infants and young children. Standards and restrictions vary by region, leading to use of non-phthalate or bio-based plasticisers in sensitive applications. The term is spelled plasticiser in British English and is sometimes spelled plasticizer in American English.