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Resumo: O óleo de mamona é um óleo vegetal que permite várias reações em seus grupos funcionais hidroxila. O ácido ricinoleico (ácido 12-hidroxioleico) compõe cerca de 90% dos ácidos graxos presentes, enquanto os outros 10% são não hidroxilados. Este trabalho teve como objetivo obter polióis a partir de misturas do óleo de mamona tipo I (OM) com dietanolamina (DEA), visando elevar o grau de reticulação dos produtos finais, para uso em circuitos eletroeletrônicos. A intenção de se introduzir a dietanolamina nas formulações de resina de poliuretana advém das dificuldades apresentadas por empresas do ramo na aquisição da trietanolamina, que atualmente se encontra sob controle de órgãos federais. Análises químicas e espectroscópicas evidenciaram a obtenção de polióis com índice de hidroxila entre 230 e 280 mgKOH/g. A cinética da reação de poliadição entre os polióis resultantes e o isocianato de isoforona (IPDI) foi acompanhada pelas mudanças nas propriedades reológicas do meio, a 60 °C. As poliuretanas apresentaram propriedades compatíveis com as dos produtos atualmente disponíveis no mercado, obtidos com trietanolamina (TEA). Palavras-chave: Óleo de mamona, dietanolamina, poliuretana, propriedades reológicas, propriedades elétricas, dureza. Preparation of Polyurethane Resins Based on Castor Oil and Diethanolamine and their Application in Electronic CircuitsAbstract: Castor oil (CO) is a vegetable oil that allows for multiple reactions in their hydroxyl functional groups. Ricinoleic acid (12-hidroxioleic acid) comprises about 90% of the fatty acids present while the remaining 10% are not hydroxylated. The aim of the present work was to obtain polyols from castor oil (CO) and diethanolamine (DEA), to improve the crosslinking degree of final products to be used in electronic circuits. The use of diethanolamine instead of triethanolamine in the polyurethane resin formulation is of special interest of companies, due to the difficulties in acquiring triethanolamine, which is controlled by the Brazilian Army. Chemical and NMR characterization showed that the polyol obtained had a hydroxyl number between 230 and 280 mgKOH/g. The kinetics of the polyaddition reaction from polyols and isophoronediisocyanate (IPDI) was evaluated employing rheological assays at 60 °C. The polyurethane based on DEA had compatible properties with the commercial products obtained from triethanolamine (TEA).

Polymer flooding is one of the chemical processes used to enhance the petroleum recovery. The injection of a polymer dissolved in water into a reservoir aims to increase the water viscosity, leading to an improvement of areal and vertical sweep efficiency of the oil that is located inside the pores of the rock formation. The polysaccharides (mainly xanthan gum) and polyacrylamides have been used extensively for this purpose by the oil industry, and several papers were published. However, it is not clear yet how to choose the best polymer for a specific rock formation. In this paper, four polyacrylamides with different structures were evaluated for polymer flooding and the results were correlated to the permeability of the sandstone's core employed. The polyacrylamides of higher average molar mass and higher radius of gyration were more effective in the enhancement of pressure inside the pore rock, especially with the decrease of rock permeability. Even in this case, no evidence of damage by polymer retention or adsorption on the pore rock was shown, indicating that the high polymers selected are good candidates to EOR.