Produção de cimento asfáltico de petróleo modificado por copolímeros elastoméricos tipo poliésteres, produzidos com polióis derivados de biomassa e ácido adípico

Abstract

In this study, polyesters were produced from polyols obtained by the oxypropylation process and adipic acid, in different proportions, with the aim of producing asphaltic petroleum cement (CAP) which can provide better results than the traditional CAP in thermal issues, durability, quality and environmental benefits. The oxypropylation process occurred with the addition of 5g of sugarcane bagasse and 25mL of propylene oxide (OP) in a sealed autoclave with pressure control at 200°C for 2 hours. The conversion of the polyol to the polyester is important because of the increase in the thermal stability of the material, its greater cross-linking and the increase in its insolubility in certain solvents. For the production of the polyesters, the reaction time was controlled and the temperature and the ratio between the polyol and the adipic acid were varied using tin chloride as the catalyst. Follow-up of the polyester production process was performed by the appearance of the band centered on the 1750 cm-1 region, characteristic of the insertion of an ester bond in the polymerized material in the infrared spectra. The thermogravimetry was used to determine which polyester produced would have the highest thermal stability with increasing temperature. In the results analyzed, the use of polyol with adipic acid in the proportions of 1:1 m/m (PP1AD160), 2:1 m/m (PP2AD160) and 3:1 m/m (PP3AD160), all produced at 160°C for 1 hour, were the conditions where the greatest efficiencies in polyester formation were obtained. In terms of thermal stability, the PP1AD160 sample was the most stable, but it was not applied in the CAP, since the idea of the project is to maximize the use of sugarcane bagasse in CAP using the least amount of adipic acid in the production of the polyesters, so samples PP2AD160 and PP3AD160 were used. The CAP blend was performed in the ratio of 84:16 m/m CAP:polyester. It was evidenced that the blend of polyester PP2AD160 with CAP was the only effective one, since in the mixture with polyester PP3AD160 there was no homogenization. Finally, the softening point of CAP modified with PP2AD160 was compared with the conventional CAP to verify if it was within the norms. Using the ring and ball method to perform the softening point test, a 2°C increase in the modified CAP was obtained when compared to the conventional one. With this it can be affirmed that the CAP modified with PP2AD160 meets the current norms. Further testing will be needed to confirm that the use of PP2AD160 polyester is a noble application.