Novel chlorinated dicumene initiators

#Many reactions carried out in chemical technology proceed under the influence of radicals, the formation of which can proceed in various ways.

#Thus, chlorination of the lateral chain of toluene -- a well-known substitution reaction -- may proceed under the influence of light, as well as of a chemical radical initiator, such as radicals formed from peroxide. Another example is the polymerization of styrene, which can be carried out under the influence of heat, as well as with the aid of a peroxide. In general, the higher reaction rate obtainable therewith is an advantage of the use of a chemical radical initiator. Among other things, a disadvantage may be by-products liberated during its degradation. Although the quantity of radical initiator used is in general very small, the concentration of formed by-products is frequently still so high, that the presence thereof in the end product may even be harmful to its quality. The latter may also occur in the case of polymers formed under the influence of radicals; the removal of by-products from these is frequently not possible.

#Use of a purely thermal polycondensation is afflicted with the drawback of a long duration, which is necessary to obtain an adequately high degree of polymerization. In order to meet this drawback, radical initiators have indeed been proposed, which begin to develop their activity only at elevated temperatures, e.g., between 150.degree. and 250.degree. C. Below this temperature, these initiators are practically stable, so that they are not used up during the "main polymerization" under the influence of heat and therefore may be added to the reaction mixture already at the beginning of polymerization. An important advantage of this characteristic is the fact that only very little of these initiators needs to be added to the mixture to be polymerized, since they only have the function to accelerate the progress of "afterpolymerization", at the beginning of which mostly not more than about 5% of the initial quantity of monomer is present.

#47 grams of dicumyl were placed in a 3-necked flask equipped with an agitator, a thermometer and a reflux cooler. 108 g. of sulfuryl chloride in 200 ml. of benzene were added thereto, whereupon 1.0 g. benzoyl peroxide was added while nitrogen was passed through.

#The mixture, which was agitated continuously, was heated to 75.degree. -80.degree. C. for 11/2 hours with reflux cooling, whereupon the excesses of sulfuryl chloride and benzene were removed at a reduced pressure. This resulted in 60 g. of raw product, which was treated with petroleum ether. An insoluble, solid fraction of 38 g. with a melting range from 100.degree. to 160.degree. C. was obtained thereby. The soluble, viscous fraction amounted to 21 g.

#The chlorine content of both fractions amounted to 15.4 and 24.7% by weight, respectively (theoretical values for the mono- and dichloro compounds were 13.0 and 23.1% by weight).