Iniferters polymerization kinetics

Nair et al. studied the kinetics of the polymerization of MMA at 60-95 °C using N,1SP-diethyl-NjW-di(hydroxyethyl)thiuram disulfide (30a) as the thermal in-iferter [142]. The dependence of the iniferter concentration on the polymerization rate was examined. The chain transfer constant of the propagating radical of MMA to 30a was determined to be 0.23-0.46 at 60-95 °C, resulting in the activation energy of 37.6 kj/mol for the chain transfer. Other derivatives 30b-30d were also prepared and used to derive telechelic polymers with the terminal phosphorus, amino, and other functional aromatic groups [143-145]. Thermal polymerization was also investigated with the end-functional poly(St) and poly(MMA) which were prepared using the iniferter 13 [146]. 

While there have been several studies on the synthesis of block copolymers and on the molecular weight evolution during solution as well as bulk polymerizations (initiated by iniferters), there have been only a few studies of the rate behavior and kinetic parameters of bulk polymerizations initiated by iniferters. In this paper, the kinetics and rate behavior of a two-component initiation system that produces an in situ living radical polymerization are discussed. Also, a model that incorporates the effect of diffusion limitations on the kinetic constants is proposed and used to enhance understanding of the living radical polymerization mechanism. 

Kinetics of Surface-Initiated Iniferter-Mediated Polymerization.288... 

As iniferters, the thiuram disulfides follow unusual kinetics and cannot be explained within the framework of the traditional view of kinetics and mechanisms of the free-radical polymerization. The special features of the iniferter process can be summarized as follows ... 

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