Obtenção de álcoois de cadeia longa a partir da cera de carnaúba

Abstract

The natural waxes like carnauba, are complex mixtures of ester compounds of fatty acids and long chain alcohols. Carnauba wax is obtained from the waxy powder from the leafs of the Copernicia sp palm, known as carnaubeira. The objective of this work was to study the production of long chain alcohols from crude carnauba wax using different methods of alkaline hydrolysis. Samples of yellow carnauba wax (type I) were filtered refined and hydrolyzed by three different processes: (1) 5 g of carnauba wax along with 100 ml aqueous potassium hydroxide 2, 5, 10, 15 and 20% (w/v) were taken at times of 15, 30, 60 and 120 min the reflux condenser at 100 °C; (2) 3 g of carnauba wax, along with 50 mL of aqueous solution of potassium 2, 5, 10 , 15, and 20% (w/v) were irradiated in a microwave oven following a time schedule and power; (3) 10 g of carnauba wax along with 200 mL of potassium hydroxide 2, 10 and 20% (w/v) were brought to the pressurized chemical reactor. After the hydrolysis process, the samples were filtered, washed, dried at 80° C/6h and turned into powder. The process yeld and acidity were measured. The hydrolysed samples were extracted with Soxhlet heptane for 4 hours and the material was analyzed by gas-chromatography-mass spectrometry to determine the composition of long chain alcohols. The samples hydrolyzed in a microwave presented the best yield and acidity index. The alcohols triacontanol (A30), dotriacontanol (A32) and tetratriacontanol (A34) were identified in samples of carnauba wax hydrolyzed by the three different processes, and the dotriacontanol was the most abundant among them.