CHEN Qiang;ZHU Lin;SU Xiuying;AN Huiyong;
Polyacrylamide/methyl cellulose semi-interpenetrating polymer networks (PAM/MC semi-IPNs) were prepared by aqueous radical polymerization at room temperature and APS, MBA, and TEMED were used as initiator, crossliking agent, and accelerator, respectively. The structure of hydrogels was characterized by FT-IR. The influence of MC content and temperature on hydrogel appearance, equilibrium swelling, and swelling kinetics of semi-IPN was investigated. The FT-IR spectra show that the peak of aminoⅠfor PAM is shifted from 1632cm-1 to 1650cm-1; the fact indicates that there is a strong hydrogen-bonding interaction between PAM and MC. The color of hydrogels becomes muddier from transparent to milky-like as MC content increasing. The equilibrium swelling of the series of hydrogels is enhanced as temperature increasing. However, at the same temperature, the equilibrium swelling of hydrogel is suppressed as MC content increasing. In addition, the size of semi-IPN hydrogels does not change much as temperature rising, it is inferred that the phase transition of MC at higher temperature does not lead to volume phase transition of semi-IPN hydrogel. All the hydrogel samples show rapid swelling properties before 100min, the swelling becomes slow down after 200min, and eventually the swelling approaches the equilibrium. The data of diffusion index (n) and swelling rate (k) infer that the temperature has great influence on the diffusion mechanism and swelling rate, whereas the hydrogel that its MC content is under 1.0% has little influence on that. The swelling of hydrogel is conformed to the second-order kinetics equation quite well under varying temperatures.
