Study of Antioxidant Properties of 5-n-Pentadecyl-2-tert-amylphenol

Abstract

This work presents the synthesis, characterization and the thermal study of 5-n-pentadecyl-2-tert-amylphenol (alkylphenol), which was synthesized by alkylation of 3-n-pentadecylphenol. For this study were employed termogravimetry (TG), derivative termogravimetry (DTG), differential scanning calorimetry (DSC), and differential thermal analysis (DTA) techniques. Hydrogenated naphthenic oil was submitted to accelerated oxidation tests in the presence and absence of alkylphenol according to modified ASTM D-2440 method. The addition of 1% of alkylphenol to the oil has reduced the carbonyl and peroxides bands areas: 1.00-1.00 (without alkylphenol) and 0.59-0.51 (with alkylphenol) respectively. The results showed that alkylphenol reduced significantly the formation of oxidation products in the oil analyzed. TG/DTG curves showed that 5-n-pentadecyl-2-tert-amylphenol is more stable than 2,6-di-t-butyl-4-methylphenol (BHT) when analyzed in different atmospheres: 143°C in air and nitrogen against 87°C in air for BHT.

Phosphorus cardanol: chemical characterization and thermal stability

“…CNSL is constituted of anacardic acid, cardanol and cardols, which are alkyl-substituted phenolic compounds, Figure 1 [13,20]. In accordance with the literature, the quantity and quality of constituents vary with the method of extraction.…”

“…The syntheses and chemical characterizations of the hydrogenated alkylated cardanol and their derivatives were described in the previous work of our group [13,27,28]. Petrobras (Brazilian Oil Company, Brazil) supplied the lubricant oil with no further distillation procedure and without additive and the Aldrich Chemical Company supplied the reagents and solvents (analytical grade).…”

“…1 H, 13 C and 31 P) spectra were recorded by AVANCE DRX 500 BRUKER spectrometer, at a frequency of 500 MHz under the following conditions: solvent, CDCl3; tetramethylsilane (TMS) as an internal standard for 1 H and 13 C, and phosphoric acid (H3PO4) for 31P. FTIR spectra were obtained by use of a FTIR spectrophotometer Shimadzu, model 8300.…”

“…Hydrogenated alkylated cardanol was synthesized by the alkylation of hydrogenated cardanol (HC) (3.3 mmol) with tert-butyl chloride (3.3 mmol) in the presence of Lewis acid (zinc chloride), according to the methodology presented in previous work [13,29,30].…”

“…Due to chemical versatility of these compounds and increasing concern with the environmental legislation on the maintenance of greenness in industrial processes led us to develop a method using a reagent that is less hazardous and non-toxic to the environment [13,14]. In this context, in the last years, the CNSL has gained importance in the development of sustainable chemistry [15] as a raw material for new primary and secondary antioxidants, flame-retardants, porphyrins, composites and biopolymers [16][17][18][19].…”