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Quick and Efficient Thermal Stability Enhancement of Micro‐Phase Separated Structure Formed from ABA Triblock Copolymers by Photo Cross‐Linking Approach
Author(s) -
Kawarazaki Isamu,
Hayashi Mikihiro,
Yamamoto Katsuhiro,
Takasu Akinori
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201904104
Subject(s) - copolymer , small angle x ray scattering , materials science , benzophenone , atom transfer radical polymerization , thermal stability , scattering , polymer chemistry , phase (matter) , chemical engineering , thermal , polymer , composite material , optics , thermodynamics , chemistry , organic chemistry , physics , engineering
We here report quick and efficient enhancement of the thermal stability of triblock copolymer‐based bulk morphologies by utilizing photo cross‐linking, which aims for widening the application range of block copolymer‐based materials. First, we synthesized ABA triblock copolymer bearing photo cross‐linkable groups (i. e., benzophenone groups) in the end blocks via two step atom transfer radical polymerizations (ATRP) and subsequent esterification reaction. UV‐light was irradiated for the annealed bulk films at room temperature, and the photo cross‐linking completely progressed within several minutes. Small angle X‐ray scattering (SAXS) and the model fitting analysis revealed that the original cylinder morphology of the neat sample was nicely preserved after the photo cross‐linking, which enables investigation of intrinsic effects of domain cross‐linking. The temperature ramp SAXS measurements demonstrated the photo cross‐linked cylinder structure remained up to the temperature (∼320 °C) much higher than the disordering temperature (∼240 °C) of the neat uncross‐linked structure.