In situ refractive index technique was used to study the gelation process in the free-radical cross-linking copolymerization (RCC) of N,N-dimethylacrylamide with N,N′-methylenebisacrylamide as the cross-linker. The change of refractive index was measured and used to monitor the gelation process. The influence of different polymerization conditions on the gelation process, such as monomer, cross-linker and initiator concentrations was investigated and discussed in detail. The kinetic model under steady-state conditions was employed to determine the monomer consumption rate during the gelation process.
Bibliographical noteFunding Information:
The National Natural Science Foundation of China (Grant No. 29774036 and 29904007) and PPLAS Foundation of the Chinese Academy of Sciences are gratefully acknowledged for the financial support to this work.
- In situ refractive index