Improvement on stain resistance of synthetic leather by plasma treatment under atmospheric pressure

Abstract

This study investigated the application of plasma treatment under atmospheric pressure to enhance stain resistance of synthetic leathers. The use of synthetic leather is popular because of its performance and low cost. Owing to its properties, synthetic leather is easily stained. This study investigated the likelihood of improving the stain resistance of synthetic leathers by plasma treatment. Three different synthetic leathers, which are popular in the market were studied. They are synthetic suede leather (100% polyester), synthetic flock leather (mainly composed of rayon) and smooth synthetic leather (manly composed of polyurethane). The single step, low pollution technique, atmospheric plasma jet (torch) was applied. The process parameters of the plasma treatment were studied and they includes flow rate of helium, flow rate of reactive gas, discharge power, jet distance, dwell time and amount of precursor. In order to fabricate a hydrophobic surface, tetramethylsilane (TMS) were used as monomers. The optimum machine settings for enhancing hydrophobicity were found. The result of static contact angle shows that liquid repellency of synthetic leather is increased after plasma treatment. Hydrophobic surface was successfully fabricated on the synthetic leathers. SEM micrographs show that granular pitches were formed on plasma treated surface. FTIR and XPS confirmed that the content of silicon based compound was increased after plasma treatment. TMS is an effective monomer on plasma deposition for surface hydrophobisation. Multiple linear regression analysis was carried out and the correlation between process parameters and result contact angle enhancement is confirmed. The amount of TMS and discharge power were strongly contributed to the contact angle enhancement. Based on the regression analysis, an equation is generated to predict contact angle enhancement with respect different process parameters.