Influência da adição de lignina no envelhecimento de tinta de demarcação horizontal viária

Abstract

The appreciation of biomass residues such as lignin has increased in recent years due to their chemical composition that allows the conversion of their macro components into a cost-effective option for usage. The effect of lignin addition on accelerated artificial aging with ultraviolet (UV) radiation, viscosity, density, storage stability, no-pick-up time, flexibility and abrasion resistance of the acrylic road marking painting was evaluated. Concentrations of 0.10wt.%, 0.25wt.%, 0.5wt.% and 1wt.% of lignin in road marking paint were added. The attenuated total reflectance (FTIR-ATR) infrared spectroscopy technique and the colorimetric assays were used to evaluate the aging of pure and acrylic paint modified with lignin. Those analyses were performed before and after exposing samples to the Weather-o-meter aging chamber (W.O.) with xenon arc fluorescence lamp radiation for 400 h and to the UV chamber with 313 UVB light radiation for 100 hours. Addition of 1% weight of lignin in the paint increased 3.4% of the viscosity, 4.7% of the specific mass and 36.3% in abrasion resistance. Lignin did not cause significant changes in the flexibility, drying-up (no-pick-up-time) and storage stability tests. The band intensity at 1142 cm-1 (C-O) decreased 40.3% and 22.9% after aging without addition of lignin in W.O. and UV respectively, indicating a cleavage of ester group. Adding 0.10%, 0.25% and 1.0% weight of lignin in the paint the relative area of the C-O peak increases after aging in W.O. indicating a beneficial effect of lignin on the photodegradation resistance. There was a decrease in the intensity of the relative area of the C-O group after aging test through UV-B radiation for all samples. The modified paint with 1% weight of lignin had the lowest decrease of 0.36% in the relative area of C-O peak indicating a higher photodegradation resistance . The protection factor obtained in this work shows that adding lignin in pavement marking paint promotes a protection against the paint yellowing. The results obtained shows the beneficial effects of the addition of lignin to horizontal signaling paint, which becomes a potential application for lignin, reducing its waste in the environment and its incineration as low value fuel