Reciclagem de PETpc na incorporação da formulação de uma tinta em pó

Abstract

The Growing use of PET packaging results in high generation of solid waste. Recycling is an alternative For a polymeric material this reuse. This study aims to evaluate the influence of incorporation of 2.5, 5 and 7.5% (m/m) of PETpc powder to replace the mineral filler barium sulfate (BaSO4) in a coating base polyester resin. Two coatings obtain procedures were used: method 1 coating was processed in twin screw extruder (conventional method) and the method 2, first resin and PETpc were extruded in the single extruder thread and after all coatings components were homogenised in twin screw extruder. The coatings were applied on carbon steel AISI 1005 samples of 70 mm x 120 mm x 0.75 mm dimensions with prephosphating treatment were used. The PETpc powder, the PET flake and powder coatings obtained were characterized from thermal analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of incorporating of PETpc powder on mechanical properties and corrosion resistance of the coatings were evaluated by gloss measurement tests, adhesion, flexibility, impact resistance, exposure to salt spray (NS) electrochemical impedance spectroscopy (EIS) and analysis of scanning electron field emission (SEM/FEG). The results showed that the incorporation of PETpc powder in the powder coatings did not affect the thermal behavior of the coatings obtained by the process 1, but reduced gloss and in the flexibility test visualized cracks in the concentration of 2.5% PETpc powder. In the coatings obtained from the process 2 was observed change in the thermal behavior of the coatings seen in the TGA and DSC testing, as well as changes in the coatings film with increase in the gloss and also in the flexibility test as with 5% PETpc powder showed the better results. Impact tests, salt spray, contact angle and grip there was no change in the results obtained with the two processes used. In test EIS powder coatings adding more than 2.5% PETpc powder showed no corrosion. Thus, the results indicate that the incorporation of PETpc powder on powder coating based polyester resin may be a promising use for improving the properties of the coating and may also be an alternative to the use of waste PETpc.