Synthesis and Characterization of Polyacrylamide and Poly(acrylamide-co-diallyldimethylammonium chloride) via Free-Radical and RAFT Polymerization

Abstract

First synthesized decades ago, arylamide-based polymers have blossomed into one of the most important polymers in the modern-day era. The uses of polyacrylamides are plentiful and varied, from their main application in waste-water treatment to paper making processes. The water solubility and large molecular weights of these polymers make them extremely useful for coagulation methods as well. Acrylamide itself reacts easily with a wide array of polyelectrolytes, expanding the function possibilities even more. Free-radical synthesis has been a vital mode of creation in previous years, but in more recent times, new and improved synthesis methods have been discovered. RAFT polymerization in particular is well-known for its ease of use and for its ability to maximize polymer content control. This research focuses on the synthesis and characterization of these acrylamide-based polymers with an intent to deepen an understanding of their polymeric properties. To do this, compounds were synthesized using acrylamide and diallyldimethylammonium chloride. Both free-radical and RAFT polymerization methods were used as well. The products were characterized using nuclear magnetic resonance, Fourier transform infrared spectroscopy, and dilute-solution viscosity tests. Thermal properties were obtained using thermogravimetric analysis and differential scanning calorimetry. The hypothesized product structures were proven correct with analysis methods. RAFT and free-radical synthesis were compared, but more in-depth research is required to isolate the differences in molecular compositions.