Semibatch RAFT polymerization for branched polyacrylamide production: Effect of divinyl monomer feeding policies

Authors

  • Dunming Wang,

    Corresponding author
    • State Key Laboratory of Chemical Engineering, Institute of Polymerization and Polymer Engineering, Dept. of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang, P.R. China
    Search for more papers by this author
  • Wen-Jun Wang,

    1. State Key Laboratory of Chemical Engineering, Institute of Polymerization and Polymer Engineering, Dept. of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang, P.R. China
    Search for more papers by this author
  • Bo-Geng Li,

    1. State Key Laboratory of Chemical Engineering, Institute of Polymerization and Polymer Engineering, Dept. of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang, P.R. China
    Search for more papers by this author
  • Shiping Zhu

    Corresponding author
    • Dept. of Chemical Engineering, McMaster University, Hamilton, ON, Canada
    Search for more papers by this author

Correspondence concerning this article should be addressed to W.-J. Wang at wenjunwang@zju.edu.cn or S. Zhu at zhuship@mcmaster.ca.

Abstract

Star and hyperbranched polyacrylamides (s-PAMs and b-PAMs) were synthesized via semibatch RAFT copolymerization of acrylamide (AM) and N,N′-methylenebisacrylamide (BisAM) using four monomer feeding policies. The BisAM to chain transfer agent (CTA) ratios from 1 to 40 at a constant [AM]0/[CTA]0 of 600 were investigated at 60°C. The s-PAMs with the number of arms of 1.4–12.8 and 1.8–8.4 were, respectively, produced by arm-first (AF) and core-first (CF) approaches, whereas the b-PAMs having the branching density of 1.34–13.1C/1000Cs were synthesized by constant BisAM feeding (semibatch polymerization, SB) and batch (batch polymerization, BA). Soluble b-PAMs were produced with the four feeding policies at [BisAM]0/[CTA]0 of 5. However, when the [BisAM]0/[CTA]0 was increased to 30, the gelation occurred with the CF and BA approaches while the AF and SB synthesized soluble branched PAMs. The AF and SB approaches appeared to be practical in producing the respective s-PAM and b-PAM at high [BisAM]0/[CTA]0 ratios or low CTA usages. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1322–1333, 2013

Ancillary