Type 1 Pilot Action:

FTPO – Analysis – terephthalic acid fractions

Goal: The aim of a FTPO-project is to develop innovative recycling methods (chemical recycling of polyethylene terephthalate (PET)) and to prove experimentally the usefulness of the obtained monomers for the synthesis of PET. In order to carry out and evaluate the polymerisation tests, it is necessary to determine the purity of the monomers obtained from the recycling process.

Approach: Different terephthalic acid fractions were provided from FTPO to be analyzed by HPLC and evaluated with regard to their applicability for polymerization. Regarding the HPLC measurements FTPO provided purified PTA (terephthalic acid) sample which contained traces of 4-CBA (4-Carboxybenzaldehyde) and a pure 4-CBA chemical. A calibration curve of the impurity was made with four different additions of 4-CBA in PTA as described in the D7884 – 13 standard. After that, the concentration of 4-CBA in all samples from FTPO was determined.

Results: The corresponding impurities of each fraction could be shown, which makes HPLC measurement a helpful tool in the production of PET in different quality levels.

Involved Partners: PCCL GmbH