An ABCA tetrablock terpolymer with
excellent thermogelling properties
in aqueous solutions has been identified by tuning the architecture
of ethylene glycol-based tetrablock terpolymers. Specifically, it
gels at concentrations as low as 5 wt % at a wide range of temperatures,
including body temperature. Nine tetrablock copolymers based on hydrophilic
oligo(ethylene glycol) methyl ether methacrylate with average molar
mass (MM) 300 g mol–1 (OEGMA300, A), hydrophobic n-butyl methacrylate (BuMA, B), and hydrophilic and thermoresponsive
di(ethylene glycol) methyl ether methacrylate (DEGMA, C) were synthesized
and screened. The MM and composition were kept constant, while the
tetrablock architecture was systematically varied. Specifically, copolymers
with (i) two OEGMA300 blocks (ABCA, ABAC, and ACAB), (ii) two BuMA
blocks (BACB, BABC, and ABCB), and (iii) two DEGMA blocks (CABC, CACB,
and ACBC) were fabricated. The self-assembly and thermoresponsive
properties of their aqueous solutions were investigated with the polymer
architecture governing their solubility, micellization, thermoresponsive,
and rheological properties.