Peroxides as Initiators for High-Pressure Polymerization

Abstract On the basis of the high-pressure polymerization of ethylene, in which organic peroxides are increasingly used as initiators, the problems which play an important part in selecting the most suitable initiators are discussed. Starting from the rate of decomposition of the initiator at the actual conditions of the high-pressure polymerization, the consumption of the initiators and its costs as well as its influence on the process control are considered. A second important point is the influence of the initiator on the properties of the polymer which can be exerted by the reaction of the initiator or its decomposition products with the polymer and the polymer chain radicals or the initiator decomposition products and residual initiator which remains dissolved in the polymer. The last part is devoted to the handling of peroxides during storage and metering in the reactor which are questions of process technology and safety techniques. The criteria discussed in respect to the choice of peroxidic initi...