Phosphate esters alcohol starting material

Another method for slowing oxidation of rubber adhesives is to add a compound which destroys the hydroperoxides formed in step 3, before they can decompose into radicals and start the degradation of new polymer chains. These materials are called hydroperoxide decomposers, preventive antioxidants or secondary antioxidants. Phosphites (phosphite esters, organophosphite chelators, dibasic lead phosphite) and sulphides (i.e. thiopropionate esters, metal dithiolates) are typical secondary antioxidants. Phosphite esters decompose hydroperoxides to yield phosphates and alcohols. Sulphur compounds, however, decompose hydroperoxides catalytically. 

There are many parallels between phosphates and sulfates of aliphatic alcohols. Both types of surfactants contain ester bonds undergoing hydrolysis in acid solutions. In that case the starting materials are received once more. By dry heating of the salts above a temperature of 140°C destruction will occur forming the corresponding alkenes and an inorganic acid salt. In the same way as sulfonic and sulfinic acids are formed by C-S bonds, C-P bonds lead to phosphonic and phosphinic acids. 

However, exclusive primary or secondary alkyl phosphates are seldom produced. That is due not only to the expenses of production but to the fact that in practical application the mixture of both esters combined with the rest of unreacted starting material often offers most interesting properties. Changing the molecular ratio of alcohol to P4O10 from 2 1 to 4 1 results in an increase of the secondary ester in the mixture from 35% to 65%. 

Mixed alkyl aryl esters may be obtained by reacting phosphorochloridates with sodium derivatives of phenols or alcohols (5.297, 5.298). Octyl diphenyl phosphate is obtained commercially by reaction (5.298), the starting material having been obtained from octyl alcohol and phosphoryl chloride by a reaction of type (5.295). 

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