Melt Polymerization of Acrylamide Initiated by Nucleophiles: A Route toward Highly Branched and Amorphous Polyamide 3

David Edinger, Hansjörg Weber, Ema Žagar, David Pahovnik, Christian Slugovc*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The melt polymerization of acrylamide initiated by nucleophiles allows for the preparation of polyamide 3 (PA 3) with a branching factor of about 1.5. The high share of branching units imparts a fully amorphous morphology featuring a low glass-transition temperature of 67 °C and renders the polymer water-soluble (430 ± 20 g/L at 25 °C). The disclosed method provides an easy, resource-efficient, and green access to a polymer interesting for applications in biological and biomedical systems. The obtained PA 3 was characterized by several NMR techniques, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, size exclusion chromatography, thermal analyses, and powder-X-ray diffractometry. Preparation and characterization of a 15N-marked polymer complemented the elucidation of the polymer structure. Mechanistically, the polymerization can be considered as an aza-Michael polymerization of acrylamide involving zwitterionic species as the key intermediates being responsible for the high degree of branching that can be controlled by the temperature at which the polymerization is carried out. The highest branching is obtained at 83 °C and decreases upon increasing the temperature.
Original languageEnglish
Pages (from-to)2018-2026
Number of pages9
JournalACS Applied Polymer Materials
Issue number4
Publication statusPublished - 9 Apr 2021


  • acrylamide
  • aza-Michael reaction
  • branched polymer architecture
  • polyamide 3
  • solvent-free polymerization

ASJC Scopus subject areas

  • Polymers and Plastics
  • Process Chemistry and Technology
  • Organic Chemistry

Fields of Expertise

  • Advanced Materials Science

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