ABA Triblock Brush Polymers: Synthesis, Self-Assembly, Conductivity, and Rheological Properties
The synthesis, self-assembly, conductivity, and rheological properties of ABA triblock brush polymers (BBCPs) with grafted polystyrene (A block, N_(PS) = 21) and poly(ethylene oxide) (B block, N_(PEO) = 45) side chains are reported. Two backbone molecular weights (N_A:N_B:N_A = 11:78:11 and 15:119:15) were investigated with lithium bis(trifluoromethane)sulfonimide (LiTFSI) doping ratios 2 ≤ [EO]:[Li+] ≤ 20. Blends with 2 ≤ [EO]:[Li+] ≤ 10 suppress PEO crystallization and self-assemble into hexagonally packed cylinders of the minority gPS component. Conductivity is on the order of 10^(–3) S/cm at 105 °C with a corresponding elastic modulus ca. 10^4 Pa. The optimum conductivity occurs at a blend ratio near 10:1 [EO]:[Li+], similar to that reported for linear block copolymer analogues.
© 2015 American Chemical Society. Received: April 28, 2015; Revised: June 18, 2015; Publication Date (Web): July 7, 2015. We thank Prof. Julia Kornfield for use of her rheometer. C.M.B. thanks the Dreyfus Foundation for Environmental Postdoc Fellowship EP-13-142. A.B.C. thanks the U.S. Department of Defense for support through the NDSEG fellowship. This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357. The authors declare no competing financial interest.
Supplemental Material - ma5b00880_si_001.pdf