TEREPHTALIC PLASTICIZERS

One of the main large-tonnage polymers of the modern chemical industry is polyvinyl chloride (PVC), which is a brittle polymer that is destroyed by heat and light. Plasticizers are used to give PVC elasticity, frost resistance and good formability.

The main plasticizer for PVC is di (2-ethylhexyl) phthalate (dioctyl phthalate, DOP). which is recognized as a reference plasticizer and with which the properties of other plasticizers are compared.

However, recently there has been a tendency to reduce the production and use of DOP due to its high toxicity (2 hazard class according to GOST 12.1.007).

Di (2-ethylhexyl) terephthalate (dioctyl terephthalate, DOTP) is the non-toxic analogue of DOP.

DOTP is obtained by reaction of terephthalic acid or its methyl esters with 2-ethylhexanol when heated in the presence of a catalyst with simultaneous distillation of the released water or methanol. At the end of the reaction, the excess of 2-ethylhexanol is removed and the resulting plasticizer is purified by known methods.

Based on the well-known technological schemes of DOTP synthesis, we have developed technologies for the production of terephthalate plasticizers, analogs of DOTP, using waste and by-products of production as raw materials.

The implementation of these technologies allows to solve two important tasks:

• professional disposal of large-tonnage waste and petrochemical by-products;
• obtainment of good quality non-toxic and inexpensive plasticizers that are in demand on the modern market.

The obtained plasticizers can be used in the manufacture of PVC products.