The effect of hydrogen bonding on intramolecular chain transfer in polymerization of acrylates

Abstract

Propagation rate coefficients (k(p) ) for 2-hydroxyethyl acrylate (HEA) have been determined by pulsed-laser polymerization (PLP) combined with size-exclusion chromatography (SEC) between 20 and 60 °C using pulse repetition rates of 50 and 100 Hz. The success of PLP-SEC under these conditions suggests that HEA is not subjected to the intramolecular chain transfer to polymer (backbiting) reactions dominant for other acrylates; (13) C NMR analysis shows that the quaternary carbon observed in PLP-generated poly(butyl acrylate) (pBA) samples is not observed in pHEA. These results are related to H-bonding in the system, as it is shown that the introduction of H-bonding by addition of n-butanol to BA suppresses backbiting, and the disruption of H-bonding by addition of dimethylformamide to HEA leads to an increased level of backbiting.