Molecular structure and properties of click hydrogels with controlled dangling end defect |
| |
| Authors: | Ao‐kai Zhang Jun Ling Kewen Li Guo‐dong Fu Tasuku Nakajima Takayuki Nonoyama Takayuki Kurokawa Jian Ping Gong |
| |
| Affiliation: | 1. School of Chemistry and Chemical Engineering, Southeast University, Nanjing, Jiangsu Province, People's Republic of China;2. Graduate School of Life Science, Hokkaido University, Sapporo, Japan;3. Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China;4. Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan |
| |
| Abstract: | In this study, controlled amount of dangling ends is introduced to the two series of poly(ethylene glycol)‐based hydrogel networks with three and four crosslinking functionality by using click chemistry. The structure of the gels with regulated defect percentage is confirmed by comparing the results of low‐field NMR characterization and Monte Carlo simulation. The mechanical properties of these gels were characterized by tensile stress–strain behaviors of the gels, and the results are analyzed by Gent model and Mooney–Rivlin model. The shear modulus of the swollen gels is found to be dependent on the functionality of the network, and decreases with the defect percentage. Furthermore, the value of shear modulus well obeys the Phantom model for all the gels with varied percentage of the defects. The maximum extension ratio, obtained from the fitting of Gent model, is also found to be dependent on the functionality of the network, and does not change with the defect percentage, except at very high defect percentage. The value of the maximum extension ratio is between that predicted from Phantom model and the Affine model. This indicates that at the large deformation, the fluctuation of the crosslinking points is suppressed for some extend but still exists. Polymer volume fractions at various defect percentages obtained from prediction of Flory–Rehner model are found to be in well agreement with the swelling experiment. All these results indicate that click chemistry is a powerful method to regulate the network structure and mechanical properties of the gels. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1227–1236 |
| |
| Keywords: | Affine model click chemistry dangling ends Gent model hydrogels mechanical properties modeling Monte Carlo simulation network inhomogeneity Phantom model structure‐property relations |
|
|
