Estudo do comportamento mecânico e características de tingimento de estruturas têxteis de meta-aramida funcionalizadas com polieletrólito Pddacl: processo ambientalmente amigável

Abstract

This study deals with a mechanical, morphological and tinctorial analysis of yarns and fabrics (Jersey Knit) produced with meta-aramid fiber. Initially, meta-aramid yarns were characterized by titration, torsion and tensile analysis. Aiming to dye the yarns with different dyes, a structure of jersey knit has been developed by using a round loom. Due to the difficulty to dye the meta-aramid fiber, a pre-treatment with a polyelectrolyte poly (diallyl dimethyl ammonium chloride) (PDDACL) has been proposed. Afterwards, the samples have been characterized before and after functionalization and dyeing by mechanical (traction, elongation, friction, pilling) and physical-chemical tests (thermogravimetric analysis, differential scanning calorimetry, contact angle, Fourier-transform infrared spectroscopy(FTIR)), complemented by scanning electron microscopy. The dyeing process has been performed with different dyestuff, such as acid dyes, reactive and basic at temperatures 110/120/130°C. In order to optimize the dyeing process by obtaining high values of color strength, the acid dye class has been used in the 3³ experimental design. The chemical effects of the functionalization of meta-aramid with PDDACL contributed to the best results obtained in the color strength values reaching k/s of 80.38 at an optimum point at 50min, 70ºC and with a concentration of 5% spm of PDDACL. The mechanical properties of the substrates treated and dyed with PDDACL were not altered. However, we have been observed a decrease in pilling, increase in hydrophobicity and better uniformity of dyeing. The meta-aramid fiber degraded at temperatures higher than 500 ° C, and for the FTIR analysis has been not possible to identify the presence of new bands besides those present in the spectrum obtained from the in-nature sample, even after functionalization. Regarding wash fastness, we have been observed a decrease in K/S values of approximately 3 times was observed, but the functionalized sample maintained values of Color strength 2-3 times higher than the values of the sample without functionalization.