Uso de superácido nas reações de esterificação da terebentina
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Tipo de produção
Dissertação
Data
2022
Autores
Mendonça, Barbara Silva
Orientador
Cella, Rodrigo
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Citação
MENDONÇA, Barbara Silva. Uso de superácido nas reações de esterificação da terebentina. 2022. 65 f. Dissertação (Mestrado em Engenharia Química) - Centro Universitário FEI, Instituição, São Bernardo do Campo, 2022. Disponível em: https://doi.org/10.31414/EQ.2022.D.131439.
Texto completo (DOI)
Palavras-chave
pineno,terebentina,acetato de a-terpenila
Resumo
Este trabalho tem como objetivo otimizar as condições de síntese do acetato de a-terpenila em uma rota direta e alternativa, a partir da esterificação do a e ß-pineno presentes na terebentina. O acetato de a-terpenila é amplamente utilizado nas indústrias de perfumaria, farmacêutica e alimentícia por se tratar de um agente aromatizante sintético. O acetato de a-terpenila possui também ação antibacteriana, anti-infecciosa, antinociceptiva e antioxidante, além de acelerar a vasoconstrição e neutralizar os odores gerados pela transpiração. A reação estudada acontece sob catalise homogênea na presença de ácido acético como solvente, sendo assim iniciou-se o estudo fazendo uso de diferentes catalisadores ácidos. Utilizando o cromatógrafo gasoso associado ao espectrômetro de massas pôde-se avaliar os resultados de conversão do pineno e a seletividade em relação ao produto de interesse e concluiu-se que o ácido fluorantimônio apresentou os melhores índices dentre os catalisadores testados. Em seguida buscou-se aprimorar as condições de reação utilizando o ácido fluorantimônio como catalisador. Comparou-se a utilização de agitação magnética e ondas sonoras e os resultados alcançados foram semelhantes no mesmo tempo reacional, sendo assim optou-se por seguir o estudo utilizando apenas a agitação magnética. A fim de alcançar a quantidade mínima de catalisador, uma vez que se trata de um superácido, estudou-se reações com diferentes cargas de catalisador e concluiu-se que a reação apresentou bons resultados, em dois casos. No primeiro caso utilizou-se uma carga de 0,5 mol% de catalisador com diluição de 1 mol/L e alcançou-se a conversão média de 99% e seletividade média de 50% em 40 minutos de reação. No segundo caso utilizou-se carga de 0,2 mol% de catalisador com diluição de 2 mol/L, e em 120 min de reação alcançou-se a conversão média de 96% e seletividade média de 57%. Para ambos os casos as reações foram analisadas ao longo do tempo, e a partir da retirada de amostra em intervalos pré-estipulados observou-se um comportamento diretamente proporcional para a conversão e inversamente proporcional a seletividade. Ou seja, com o passar do tempo a conversão aumenta enquanto a seletividade diminui devido as reações secundárias que ocorrem com o produto formado ainda na presença do catalisador. Por último, testou-se a influência da temperatura em dois cenários de aquecimento, ambos com a concentração de 1 mol/L e constatou-se que logo nos primeiros 20 min de reação a conversão já era total. No primeiro caso a carga de catalisador foi de 0,5 mol%, a reação ocorreu à 50°C e a seletividade alcançou o índice médio máximo de 26%. Já no segundo caso, no qual
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utilizou-se 0,2 mol% de carga de catalisador e o meio reacional foi mantido à 80°C, o índice de seletividade máximo foi de apenas 6%. A partir dessa análise descarta-se a necessidade do aquecimento uma vez que os resultados de seletividade em relação ao produto de interesse à temperatura ambiente são mais expressivos
This study has the objective of optimizing the synthesis conditions of a-terpinyl acetate in an alternative one-step route, from the esterification of a and ß-pinene present in the turpentine. The a-terpinyl acetate is broadly used in the perfumery, pharmaceutical and food industries because it is a synthetic flavoring agent. The a-terpenyl acetate also has antibacterial, anti-infective, antinociceptive and antioxidant action, in addition to accelerating vasoconstriction and neutralizing odors generated by perspiration. The studied reaction happens under homogeneous catalysis in the presence of acetic acid as a solvent, therefore the study began using different acid catalysts. Using gas chromatography associated with the mass spectrometer, it was possible to evaluate the results of the conversion of pinene and the selectivity in relation to the product of interest, and it was concluded that the fluoroantimonic acid presented the best indexes among the catalysts tested. Then, it was sought to improve the reaction conditions using fluoroantimonic acid as a catalyst. The use of magnetic agitation and sound waves was compared and the results achieved were similar in the same reaction time, so it was decided to continue the study using only magnetic agitation. In order to reach the minimum amount of catalyst, since it is a superacid, reactions with different catalyst charges were studied and it was concluded that the reaction presented good results in two cases. In the first case, a load of 0.5 mol% of catalyst was used with a dilution of 1 mol/L, an average conversion of 99% and an average selectivity of 50% were achieved in 40 minutes of reaction. In the second case, a load of 0.2 mol% of catalyst was used with a dilution of 2 mol/L, and in 120 min of reaction, an average conversion of 96% and an average selectivity of 57% was reached. For both cases, the reactions were analyzed over time from the sample withdrawal at pre-specified time intervals and a behavior directly proportional to the conversion and inversely proportional to the selectivity was observed, that is, over time, the conversion increases while the selectivity decreases due to secondary reactions that occur with the product formed still in the presence of the catalyst. Finally, the influence of temperature was tested in two heating scenarios, both with a concentration of 1 mol/L and it was found that in the first 20 min of reaction the conversion was already complete. In the first case, the catalyst load was 0.5 mol%, the reaction took place at 50°C and the selectivity reached the maximum average index of 26%. In the second case, in which 0.2 mol% of catalyst load was used and the reaction was kept at 80°C, the maximum selectivity index was only 6%. From this analysis, the 9 need for heating was discarded since the results of selectivity in relation to the product of interest at room temperature are more expressive
This study has the objective of optimizing the synthesis conditions of a-terpinyl acetate in an alternative one-step route, from the esterification of a and ß-pinene present in the turpentine. The a-terpinyl acetate is broadly used in the perfumery, pharmaceutical and food industries because it is a synthetic flavoring agent. The a-terpenyl acetate also has antibacterial, anti-infective, antinociceptive and antioxidant action, in addition to accelerating vasoconstriction and neutralizing odors generated by perspiration. The studied reaction happens under homogeneous catalysis in the presence of acetic acid as a solvent, therefore the study began using different acid catalysts. Using gas chromatography associated with the mass spectrometer, it was possible to evaluate the results of the conversion of pinene and the selectivity in relation to the product of interest, and it was concluded that the fluoroantimonic acid presented the best indexes among the catalysts tested. Then, it was sought to improve the reaction conditions using fluoroantimonic acid as a catalyst. The use of magnetic agitation and sound waves was compared and the results achieved were similar in the same reaction time, so it was decided to continue the study using only magnetic agitation. In order to reach the minimum amount of catalyst, since it is a superacid, reactions with different catalyst charges were studied and it was concluded that the reaction presented good results in two cases. In the first case, a load of 0.5 mol% of catalyst was used with a dilution of 1 mol/L, an average conversion of 99% and an average selectivity of 50% were achieved in 40 minutes of reaction. In the second case, a load of 0.2 mol% of catalyst was used with a dilution of 2 mol/L, and in 120 min of reaction, an average conversion of 96% and an average selectivity of 57% was reached. For both cases, the reactions were analyzed over time from the sample withdrawal at pre-specified time intervals and a behavior directly proportional to the conversion and inversely proportional to the selectivity was observed, that is, over time, the conversion increases while the selectivity decreases due to secondary reactions that occur with the product formed still in the presence of the catalyst. Finally, the influence of temperature was tested in two heating scenarios, both with a concentration of 1 mol/L and it was found that in the first 20 min of reaction the conversion was already complete. In the first case, the catalyst load was 0.5 mol%, the reaction took place at 50°C and the selectivity reached the maximum average index of 26%. In the second case, in which 0.2 mol% of catalyst load was used and the reaction was kept at 80°C, the maximum selectivity index was only 6%. From this analysis, the 9 need for heating was discarded since the results of selectivity in relation to the product of interest at room temperature are more expressive