Dynamics of Poly(methyl methacrylate)in Ionic Liquids with Different Concentration and Cationic Structures  

作　　者：Huan Luo Xi He Gang Liu Yan-Hua Niu Guang-Xian Li 

机构地区：[1]College of Polymer Science and Engineering,State Key Laboratory of Polymer Materials Engineering of China,Sichuan University,Chengdu,610065,China

出　　处：《Chinese Journal of Polymer Science》2023年第2期315-324,共10页高分子科学（英文版）

基　　金：the National Natural Science Foundation of China(Nos.51873125,52073184 and 51721091);Scientific Research Foundation of International Cooperation and Exchanges of Sichuan Province(No.2019YFH0027).

摘　　要：The dynamic behavior of entangled poly(methyl methacrylate)(PMMA)chains in both the traditional monocationic ionic liquid(MIL)and synthetic dicationic ionic liquid(DIL)with the same anion bis[(trifluoromethyl)sulfonyl]imide([TFSI]−)has been examined over the wide composition range using differential scanning calorimetry and rheological measurements.PMMA/DIL and PMMA/MIL systems exhibit two glass transitions in the midrange of composition due to self-concentration effects.PMMA in DIL shows slower relaxation behavior,however,after the iso-free-volume correction,the terminal relaxation timeτ_(0)of PMMA in both the DIL and MIL presents the power law behaviorτ_(0)∼ϕ^(v)with exponent v conforming to experimental results for conventional polymer solutions(v=2.0±0.2).At high ILs concentration(70%),the entanglement molecular weight M_(e)of PMMA/DIL system is lower than that of PMMA/MIL system owing to the formation of additional physical network in DIL,while the difference of M_(e)is reversed at low ILs content.The composition dependence might be related to the fact that the probability of formation of physical cross-linking points in linked double imidazolium ring increases with the increase of DIL content.The recovered creep strain of PMMA/DIL is almost 18 times of PMMA/MIL,exhibiting significantly better viscoelastic behavior.

关 键 词：Ionic liquids Terminal relaxation time Entanglement molecular weight Creep-recovery behavior 

分 类 号：TQ323.4[化学工程—合成树脂塑料工业]