Study on the gelation behavior of concentrated polyacrylonitrile/dimethyl sulfoxide solution
The gelation behavior of concentrated polyacrylonitrile (PAN)/dimethyl sulfoxide (DMSO) has been investigated via dynamic rheology. By first cooling and then heating a PAN/DMSO solution with 23 wt% PAN, thermoreversible gelation was observed. Another solution with 23 wt% PAN was first aged at 25 ℃ to gel, and then subjected to strain sweep at the same temperature. The results showed that PAN gel structure recovered immediately once disrupted, implying that the dipole-dipole attraction may play the role of cross-links in the gel. Two solutions with 20 wt% and 23 wt% PAN were cooled under different shear frequencies. The loss tangent tan δ crossed over at a certain temperature for both solutions, which was regarded as Tg. Tg increased with the increase of PAN concentration, ascribed to easier aggregation and thus cross-linking of PAN molecules at elevated concentration. However, the relaxation exponent n values were similar, indicating the unique critical structure of PAN gel regardless of concentration.
TAN Lianjiang PAN Ding
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University, S State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University,
国际会议
2009 International Conference on Advanced Fibers and Polymer Materials(2009年先进纤维与聚合物材料国际学术会议)
上海
英文
296-298
2009-10-21（万方平台首次上网日期，不代表论文的发表时间）