DOTP plasticiser, synthesis from consumer PET bottles!

Synthesis of DOTP Plasticizer for PVC from Terephthalic Acid Based on the Chemical Recycling of Post consumer PET Bottles

Terephthalic acid (TPA) having 92% purity was obtained from the chemical recycling of post-consumer PET bottles using NaOH as a catalyst in non-aqueous ethylene glycol at 180 o C for 1 hour. Direct esterification of the obtained TPA and 2-ethyl-1-hexanol at 160 o C for 6 hours yielded dioctyl terephthalate or DOTP. The resulting DOTP was clear and slightly yellowish with a specific gravity of 0.936, a refractive index of 1.472 and an acid value of 0.0044 mg KOH/g. The possibility of using DOTP as a plasticizer for PVC was studied. The mechanical properties using DOTP and a commercial plasticizer (DOP), both were investigated. It was found that the tensile strength of DOTP-plasticized PVC and that of DOP-plasticized PVC were comparable but DOTP-plasticized PVC had a higher modulus than DOP-plasticized PVC.These results suggest that DOTP can be used as a plasticizer for PVC as DOP is.