Non-phthalate Plasticisers

Phthalates have a strong cost advantage over the competition, and alternatives are used only when phthalates are unsatisfactory. Other plasticisers include the citrates, trimellitates, adipates, sebacates, maleates, gjutarates, palmitates, oleates, stearates, laurates, benzoates, aromatic phosphates, the alkyl sulfonates of phenol, and derivatives of petroleum and of butene. There 

The most widely used alternatives are ahphatic esters, together with aromatic phosphates, the trimellitates, citrates, the aliphatic polyesters and the epoxidised vegetable oils. 

Ahphatic esters such as adipates, azelates and sebacates enable PVC to remain flexible even in arctic climates. Di-octyl sebacate is especiaUy eflective in this respect, but expensive. Adipates are widely used in food packaging film because of their acceptability under food contact regulations. They have a low viscosity, making them convenient for PVC paste formulations. Examples include di-iso-nonyl adipate and benzyl octyl adipate. 

Trimelhtates such as tri-2-ethylhexyl trimellitate are fairly similar in chemical structure to phthalates, but they have improved high-temperature resistance and low volatihty, so they are used in high-temperature wire and cable applications. Their UV resistance is rather limited. 

Citrates are considered low-hazard plasticisers. Acetyl tributyl citrate has been used in food packaging film while butyryl tri-n-hexyl citrate has been evaluated for medical devices. Phosphates (tricresyl or triphenyl) are favoured where flame retardancy is at a premium, notably cable insulation. 

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Phthalate plasticisers have historically served as the preferred plasticisers to impart flexibility to PVC and several other polar polymers. They provide a desirable balance of cost and performance properties. Their acceptable and safe use is unmatched in medical appliances, food processing and packaging applications, as well as many other end uses. Potential alternatives do not have the historical record of acceptable performance found with phthalate plasticisers. Nevertheless, the Precautionary Principle has caused certain segments of society to clamour for alternatives to phthalate plasticisers. Known non-phthalate plasticisers are reviewed, and comparisons to the traditional General Purpose (GP) phthalate plasticisers are provided General Purpose plasticisers are those that impart optimum overall performance properties in PVC at lowest cost. 6 refs. USA... 

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