Dynamic rheology studies of in situ polymerization process of polyacrylamide-cellulose nanocrystal composite hydrogels
Document Type
Article
Publication Date
2-1-2011
Abstract
A series of dynamic small-amplitude oscillatory shear experiments for in situ polymerization process of polyacrylamide-cellulose nanocrystal (PAM-CNC) nanocomposite hydrogels were performed to investigate the relationship between rheological properties and synthesis parameters including chemical cross-linker concentration, polymerization temperature, initiator concentration, and CNC aspect ratios. The results showed that CNCs accelerated the onset of gelation (t onset) and acted as a multifunctional cross-linker during the gelation reaction. The composite hydrogels exhibited enhanced steady-state elastic modulus (G∞′) and plateau loss factor (tanδ) compared to these of the pure PAM hydrogels, indicating that adding CNCs not only reinforced but also toughened PAM hydrogels. ({G ∞′) and the effective network junction density (N) increased with increased cross-linker concentration, polymerization temperature, and CNC aspect ratios, but decreased with increased initiator concentration. The changes of plateau tanδ were opposite to that of G∞′. The sol-gel transition kinetics of PAM-CNC hydrogels accelerated with increased cross-linker concentration and polymerization temperature and, however, reached optimization at 0.25 wt% of initiator concentration. CNCs with lower aspect ratios promoted t onset and the sol-gel transition of PAM-CNC hydrogels, suggesting the fact that CNCs with lower aspect ratios further facilitated the formation of network of PAM-CNC nanocomposite hydrogels. © 2010 Springer-Verlag.
Publication Source (Journal or Book title)
Colloid and Polymer Science
First Page
247
Last Page
255
Recommended Citation
Zhou, C., Wu, Q., & Zhang, Q. (2011). Dynamic rheology studies of in situ polymerization process of polyacrylamide-cellulose nanocrystal composite hydrogels. Colloid and Polymer Science, 289 (3), 247-255. https://doi.org/10.1007/s00396-010-2342-3
