Polyester-Polyvinylalcohol Hydrophilization Strategies

Poly (ethylene terephthalate) (PET), also commonly called as polyester, is the most widely used polymer for the production of synthetic fibres over the past fifty years. The frequent use of this PET is due to its high mechanical strength combined with other properties such as the resistance to chemical products, stretching and abrasion. The fibre’s hydrophobicity also impacts the difficulty of cleaning these materials [1, 2]. Previous works shows that treatment with concentrated NaOH solutions can greatly improve hydrophilicity of PET fibre [1, 2, 3, 4]. However a significant decrease of mechanical properties takes place during this process. In this work, chemical strategies to counteract this negative effect and further increase the hydrophilicity of PET fibre’s has been tested. In particular, the effect of polyvinyl alcohol (PVA) and N, N ́-dimethylol-4, 5-dihydroxyethyleneurea (DMDHEU) chemically modified resin in the functionalization of saponified PET was carefully analysed. The treated fabrics were characterized by scanning electron microscopy (SEM), contact angle, ATR-FTIR spectroscopy and differential scanning calorimetry (DSC). When the best process conditions were considered for PVA-DMDHEU application, the modified PET presented a contact angle of 33.9o, stain release grade of 4 and a 45.6% increase in its mechanical properties when compared to saponified PET.