Synthesis and Characterization of Star Polyacrylamides Using Poly(ethylene imine) as a Core via Photopolymerization in Water

Water-soluble thioxanthone-terminated poly(ethylene imine) (PEI 600, PEI 1800, PEI 3000 and PEI 10000; 600, 1800, 3000 and 10000 are the weight-average molecular weights of the above PEIs, respectively). Macrophotoinitiators were synthesized by introducing a certain amount of thioxanthone (TX) moieties into the periphery of PEI, and the products were confirmed by 1H-NMR, FT-IR, and elemental analysis. Star polyacrylamides (PAMs) were prepared using the obtained macrophotoinitiator as a core via photopolymerization. The effect of the molecular weight of the macrophotoinitiator on photoinitiation efficiency of the resulting polymers was investigated. The result shows that the choice of the macrophotoimitator has no influence on the rate of polymerization. In addition, three plots of characteristic properties with the star polymer were studied to confirm the existence of arms in the resulting star PAM.