Desenvolvimento de espumas de poliuretano revestidas com formas alotrópicas de carbono para utilização como sorvente de petróleo e outras substâncias orgânicas

Abstract

The growing exploration and transportation of oil and by-products in marine environments, together with the discovery of the pre-salt in the Brazilian coast in 2006, brings potential environmental disasters caused by accidents of oil spillage in marine environments. Several materials are currently being developed and studied to minimize the environmental impacts caused by these oil spills. Among these materials, the use of sorbent materials for the effluent treatment in the separation and collection of oil from the aqueous environment. In this study, a sorbent material was developed from polyurethane foam coated with allotropic forms of carbon, with hydrophobic and oleophilic characteristics, reusable and with a higher sorption capacity than the products currently on the market for oil removal from the surface of the sea. For this, polyurethane foams were formulated from different theoretical densities (8, 14, 20, 35 and 50 kg.m-3), among which samples with better performance were selected from the characterization related to mechanical and sorption properties. With a defined foam (theoretical specific mass foam of 8 kg.m-3), two coating methods were evaluated, was added to a presonicated carbon backbone dispersion, varying the solvent used (ethanol and Petroleum ether). In addition, two oxides of graphene were synthesized from flake graphite and micronized graphite. The carbon nanostructures (graphite, graphene and carbon nanotubes) were dispersed in solution by sonification to chemically coat the foams in order to make them selective to oil. The coated foams (sorbents) were characterized as morphology, mechanical, thermal, sorption and reuse properties. The best results were obtained for the samples coated with micronized graphite, single wall carbon nanotubes functionalized with –COOH and multiple wall carbon nanotubes functionalized with –COOH, which presented a sorption oil capacity of approximately 64, 65, 70 and 58 g.g -1, which for uncoated foam was 18 g.g -1. These developed sorbents presented hydrophobic and oleophilic characteristics, fine performance in the reuse test and a reduction of saturation with application of the coatings in relation to uncoated foam between 48 and 76%. Thus, it was possible to obtain a reusable sorbent with hydrophilic and oleophilic characteristics, high sorption capacity and great potential to be used in the remediation of disasters involving the spillage of oil and others. [resumo fornecido pelo autor