Modification of Polyester Properties through Functionalization with PVA

Abstract

Due to the growing demand of the textile market, the production of synthetic fibers like polyester (PET), has been increasing compared to any other existing fiber group. However, this type of fiber has its own disadvantages, the main one being its hydrophobic nature. To improve its properties, it was sought to develop a chemical functionalization. This process consisted of three steps, the first one being the cleaning of the polyester with hydrochloric acid, followed by a subsequent hydrolysis of the textile substrate in an alkaline medium in the presence of sodium hydroxide. The last phase, that concerns the textile substrate functionalization with poly (vinyl alcohol), more commonly known as PVA, was made by a process of exhaustion at different pH values (3, 6, and 10), followed by a curing, which allowed the formation of bonds between the PVA and the polyester fibers and consequently improve polyester properties, namely the hydrophilicity, presenting a contact angle of 0º. This process of functionalization of the polyester with PVA at acidic pH, led to very promising results since a significant improvement of its properties was obtained. The functionalized and original polyester samples were further characterized through the application of several techniques, such as SEM, FTIR-ATR and differential scanning calorimetry DSC. These characterization techniques allowed to prove that the textile substrates were effectively modified. It can be concluded that, properties such as, contact angle, tensile strength, air permeability, coefficient of friction and water vapor permeability, were substantially improved by the functionalization of the polyester fabric with PVA.