Synthesis and Antioxidancy of Some n‐Alkyl, t‐Alkyl, Homologous and Isomeric Lipidic Alkylthiobisphenols

Abstract

To study the relationship between structure and properties of members of the lipidic thiobis phenol series, as extreme pressure additives in lubricants, a series of homologous compounds has been synthesised by the reaction of alkylphenols with sulphur dichloride. The isomeric n-nonylphenols have been reacted to form the C9 isomeric 2,2¢-and 4,4¢-thiobisphenols. Longer alkyl sidechains resulted mainly in the formation of 4,4¢-thiobisphenols and some of the 2,2¢ isomer. With short alkyl, particularly t-alkyl side-chains, steric hindrance resulted in the 2,2¢-compound. Additive studies have indicated that the longer chain 4,4¢ compounds possessed antioxidant properties comparable and superior to former commercial branched chain 2,2¢ compounds produced from petrochemical intermediates.

Controllable Synthesis and Synergistic Antioxidation Mechanism of Poly(p-methoxyphenol-phenylamine) in Biodegradable Vegetable-Based Lubricating Oils

“…It has been reported that the polymerization of phenol under the catalysis of horseradish peroxidase can take place on the hydroxyl group of phenol at the ortho or para positions. 40 Since pure aniline cannot be polymerized under the catalysis of horseradish peroxidase but can be copolymerized with pmethoxyphenol, p-methoxyphenol and aniline were used as the raw materials to prepare P(MOP-PA) in this research. 27 The para position of p-methoxyphenol is occupied by a methyl group, so only phenol hydroxyl and the ortho position of the phenol hydroxyl can copolymerize with aniline.…”

Enzymatic Oligomerization of p-Methoxyphenol and Phenylamine Providing Poly(p-methoxyphenol-phenylamine) with Improved Antioxidant Performance in Ester Oils

“…Commonly used antioxidants which are suitable for lubricating oils include hindered phenol derivatives, , amine derivatives, , organic sulfide, and organometallic antioxidants . Among these antioxidants, amine-type antioxidants, because of their outstanding performance, are widely used in various lubricating oils.…”

“…6,7 In this respect, it is imperative to introduce antioxidants to prevent synthetic ester oils from oxidative degradation, thereby prolonging their service life in tribological applications. 8 Commonly used antioxidants which are suitable for lubricating oils include hindered phenol derivatives, 9,10 amine derivatives, 11,12 organic sulfide, 13 and organometallic antiox-idants. 14 Among these antioxidants, amine-type antioxidants, because of their outstanding performance, are widely used in various lubricating oils.…”

Phosphorus cardanol: chemical characterization and thermal stability

“…In accordance with the literature, the quantity and quality of constituents vary with the method of extraction. The CNSL extracted from the shells by mechanical expulsion contain a mixture of anacardic acid, cardanol and cardols in smaller quantities and the CNSL obtained by the hot oil process is entitled "technical CNSL", due to the decarboxylation of the anacardic acid and subsequent formation of cardanol [21][22][23] Therefore, considering the great importance of this group of molecules and their potentiality for the development of new eco-friendly compounds, the present study shows the investigation of the thermal and oxidative stability, and antioxidant effectiveness of a phosphorus compound derived from the main constituent of technical CNSL: the cardanol. This constituent after catalytic hydrogenation (3-n-pentadecylphenol or hydrogenated cardanol) was used as raw material of this investigation.…”