Direct Determination of Interchain Transfer Constants of Benzyl Acrylate to Poly(Ethyl Acrylate) by RAFT Polymerization and Polymer Chromatography

Interchain transfer is an important side reaction in radical polymerization of acrylates and has significant effects on both reaction kinetics and the resulting polymer microstructures. In this study, an effective method for direct determination of the interchain transfer constant (C-tr) is established via the combination of RAFT polymerization of a monomer in the presence of another prepared polymer and subsequent separation using polymer chromatography. The C-tr of benzyl acrylate (BzA) to poly(ethyl acrylate) (PEA) is determined with benzyl N-carbazole dithiocarbamate (BCBD) as the RAFT agent and the effects of polymerization recipe, such as BzA/BCBD mole ratios, BzA/PEA mass ratios, and solvent amounts on C-tr determination investigated. The results indicate that interchain transfer reactions show clear short chain radical effects in early stage of RAFT polymerization and the experimental recipes have little influence on the determination. The C-tr values are in the range of 1-2 x 10(-4) at 90-120 degrees C and the activation energy of C-tr at 47.8 kJ mol(-1).

Automated summary

In this study, an effective method for direct determination of the interchain transfer constant (C-tr) in radical polymerization of acrylates was established. Experimental results showed that interchain transfer reactions exhibit clear short chain radical effects in the early stage of RAFT polymerization.