Rheological Study of Order-to-Disorder Transitions and Phase Behavior of Block Copolymer–Surfactant Complexes Containing Hydrogen-Bonded Small Molecule Additives

• DOI: 10.1021/ma501816d
• Publication Date: 2014-11-12T13:48:37Z
• Authors: Rohit Kothari; H. Henning Winter; James J. Watkins
• Keywords: Propylene oxide

Dynamic mechanical measurements were used to investigate the effect of small molecule additives on order-to-disorder transitions (ODTs) Pluronic, poly(ethylene oxide) (PEO)–poly(propylene (PPO)–PEO triblock copolymer surfactant melts. The contain multiple functional groups (carboxyl or hydroxyl), which selectively interact with PEO component Pluronic via hydrogen bonding, thereby effectively increasing χ system and leading microphase separation in otherwise disordered ODTs these Pluronic/small-molecule-additive complexes can be detected by rheology since, upon temperature, crossing transition temperature (TODT) results a sharp decrease low frequency storage loss moduli (G′ G″, respectively). crystallization is suppressed additive loading due strong bond interactions. TODT strongly composition dependent increases up 145 °C for 20 wt % particular additive. also found vary widely but systematically number, position hydrogen-bond-donating ability Upon high loadings, macrophase occur before ODT detected.