The nature of the products obtained by refluxing styrene and drying oils in xylol solution. II.Additional data on the styrene‐Tung oil reaction

An examination has been made of the reaction products obtained by refluxing a mixture of equal weights of styrene and tung oil in xylol solution in the absence of polymerization catalysts. Copolymerization occurs between styrene and tung oil. Saponification of the copolymer yields two main types of styrenated elaeostearic acid. One, which gives an insoluble potassium salt, contains styrene combined with elaeostearic acid in the approximate average molecular ratio of 8 : 1. The other styrenated acid, which is soluble in light petroleum and yields a soluble potassium salt, approximates in composition to a product derived from 1 molecule of styrene and 1 molecule of elaeostearic acid. In the conditions described, about 60% of the styrene remains unpolymerized and none forms a self‐polymer. Only about 60% of the available elaeostearic groups take part in copolymer formation, the remaining 40% being recoverable in a styrene‐free form. It is believed that the 1 : 1 styrenated acid is formed by a Diels‐Alder mechanism.