Filmes automontados de polietilenoimina/argila para revestimento de poliamida 6 com tratamento superficial.

Abstract

In this work self-assembly films were deposited on the surface of specimens of polyamide 6 (PA6). These films were obtained by the technique of layer-by-layer (LbL). It was used A positively charged hydrosoluble polyelectrolyte: the branched polyethyleneimine (PEI) and a nanoparticle of negative charge: regional sodium bentonite clay, with trade name Brasgel. These constituents were dispersed in deionized water at concentrations of 0.1%, 0.2%:, 0.5% and 1.0% by weight of clay and 0.1% of PEI, and deposited on the surface of specimens (CPs) of PA6. In the first stage of the work, the self-assembly films were deposited on the substrate (PA6) without surface treatment. In the second stage, modifications were carried out on the surface of the substrate for hydrogen peroxide (H2O2), plasma at low pressure with gaseous atmosphere of argon, oxygen and nitrogen and by the carbodiimide method. The substrate (PA6) without and with application of LbL was submitted to x-ray diffraction (XRD), scanning electron microscopy (SEM), vertical flammability UL94 test, atomic force microscopy (AFM) and the infrared spectroscopy (FTIR). By DRX, it was realized that the increased concentration of clay, in the dispersion of layers preparation, resulted in the appearance of the characteristic peak of montmorillonite. By SEM, it was observed that there was a change on the surface of the substrate submitted to the treatment and that there was an accumulation of clay particles in the samples with self-assembly layers. The PA6 without surface treatment and with application of self-assembly layers, was classified as V-2, through the UL94 test. The samples treated with H2O2 and plasma presented lower values of contact angle, while by the carbodiimide method the value of contact angle was higher than the PA6 without treatment. By AFM, it was observed an increase of roughness on the substrate surface for the samples treated by plasma. Absorption bands from the clay were observed in the spectrum of some samples. In general, self-assembly layers were obtained with success in the substrate of PA6, showing greater uniformity for samples with surface treatment.