General characteristics of transfer reactions

The activation energy of the rate constant k of reaction (1) is generally different (usually higher) from that of By lowering the polymerization temperature, transfer is relatively suppressed. Lowering of the polymerization rate is caused by the re-initiation rate constant, kj [reaction (2)], when the latter is lower than p. When it is much lower, we speak of degradative transfer. On the other hand, polymerization is not accelerated in practice when k fc. The more rapid addition of one monomer per several  

In most cases it is much easier to determine the ratio of the transfer and propagation rate constants, kjk = than the value of k. The ratio C J is called the apparent transfer constant. Formally, transfer may be regarded as copolymerization with the transfer agent XT acting as a non-polymerizing monomer . 

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