Antioxidants lonol

Two of the abstraction reactions listed in Table 6 will be discussed further viz. (a) the reaction of n-heptyl radicals with tetramethyl-ethylene which was studied specifically to help elucidate the conditions under which the reactions take place and (b) the reaction of peroxy-radicals with an oxidation inhibitor 2,6-di-t-butyl-4-methylphenol (lonol) which is of particular interest in that two distinct mechanisms have been proposed to account for its antioxidant properties. 

The oxidation is followed by reaction of the ferrous iron produced, with 2, 2 -dipyridyl to form a coloured complex, the intensity of which is proportional to the concentration of antioxidant present. The procedure has been applied to various phenolic and amine type antioxidants, namely, Succanox 18, BHT, lonol (2,6-di-tert-butyl-p-cresol), and Nonox Cl (N-N-di- 3-napthyl-p-phenylenediamine). A typical application of the procedure is given next, namely to the determination of down to 0.01% of Santonox R in PE. As the Metcalfe and Tomlinson [5] procedure determines Santonox R only in its reduced form, it does not include any Santonox R which may be present in the oxidised form in the original polymer, for example produced by atmospheric oxidation of the additive during polymer processing at elevated temperatures. Total reduced plus oxidised Santonox R can be determined by UV spectroscopic procedures. 

Antioxidants Alkylated phenols lonol 1 Sjmergism sometimes... 

Another category of compounds that play the role in diminution of oxidation rate are 3,5-di-t-butyl-4-hydroxy derivatives of ethane and ethene [02J1, 02J2]. Their efficiency in the scavenging of radicals in the competition with the reaction with oxygen occurs with a rate comparable with the rate of good commercial antioxidants like Cyanox 2246 or lonol. 

Butylated hydroxytoluene (BHT, also formerly known as lonol, E321) is 3,5-di-tert-butyl-4-hydroxytoluene (11-12). In comparison with BHA, BHT is somewhat more effective as an antioxidant of animal fats. The formation of a BHT radical and its reactions are shown in Figure 11.10. 

The procedure has been applied to various phenolic and amine type antioxidants, viz. Succanox 18, butylated hydroxy toluene, lonol (2,6-di-tert-butyl-p-cresol) and Nonox Cl (N-N-di-2-napthyl-p-phenyIenediamine)... 

Phenolic antioxidants including dicresylol propane and Santonox R ((4-4, -thio-bis-(3-napthyl-6-tert butyl phenol Phenolic antioxidants including Succonox 18, butylated hydroxy toluene, lonol, (2,6-di-tert butyl-p-cresol). Nonox Cl (N-N di-beta napthyl-p-phenylenediamine, Santonox R (4,4 thio-bis-3 methyl-6-tert-butylphenol) Phenolic antioxidants including Agerite Alba ((hydroquinone monobenzyl ether), Agerite Spar (styrenated phenol),... 

METHOD 5 - DETERMINATION OF lONOL PHENOLIC ANTIOXIDANT IN POLYETHYLENE. ULTRAVIOLET SPECTROSCOPY. 

A method for the determination of lonol antioxidant in amounts down to 0.01% in polyethylene. 

Antioxidants such a lonol CP (2,6,di-tert-butyl / -cresol), lonox 330 (1,3,5-tri-methyl-2,4-6-tri(3,5-di-tert-butyl-4-hydroxybenzyl)benzene), Polygard (tris (nonylated phenyl) phosphite), Wingstay T (described as a butylated cresol), and Wingstay W and many others, do not interfere in this procedure. 

Determination of lonol phenolic antioxidant in polyethylene. Ultraviolet spectroscopy... 

A soln. of phenyldichlorophosphine and commercial isoprene containing lonol (2,6-di-fert-butyl-p-cresol) as antioxidant allowed to stand 5-7 days at room temp, in a stoppered flask, the resulting 1,1-dichloro-1-phenyl-3-methyl-1-phospha-3-cyclopentene stirred into ice-water, and stirring continued until essentially all of it is dissolved 3-methyl-l-phenyl-l-phospha-3-cyclopentone 1-oxide. Y 57-63%.—This is a general reaction, and there can be a wide variety of alkyl, aryl, and halogeno substituents on the diene and phosphorus. W. B. McCormack, Org. Synth. 43, 73 (1963). 

---