Plasticizers

Plasticizers are additives used to increase the flexibility, workability, and durability of polymers by reducing the intermolecular forces between polymer chains and lowering the material’s glass transition temperature. They are especially common in polyvinyl chloride (PVC) products but are also used in coatings, elastomers, and adhesives to improve pliability and processability.

Most plasticizers are small, low-volatility molecules that insert themselves between polymer chains, creating free volume and enhancing segmental mobility. This reduces stiffness and makes the material easier to process, bend, or stretch. Some plasticizers are physically blended and may migrate over time, while others can be chemically bonded to the polymer to reduce leaching.

Types of plasticizers include:

- Phthalates, the traditional class of diesters of phthalic acid, such as DEHP, DINP, and DIDP, which are common in PVC but face regulatory restrictions in some applications.

- Non-phthalate plasticizers, including adipates, sebacates, citrates, and phosphates, often used as alternatives to phthalates.

- Reactive or durable plasticizers, which form covalent bonds with the polymer to resist migration.

Applications span PVC films and cables, flooring, upholstery, coatings, and sealants, as well as some specialty polymers. Safety and environmental considerations are important; several phthalates have been restricted or substituted in toys and childcare articles due to health concerns, and migration of plasticizers into food or skin contact is monitored. In response, industry trends favor non-phthalate and polymeric plasticizers, as well as bio-based and less volatile formulations.

---