Aqueous Assembly and Hydrogel Rheology of Sustainable Glyoxylate-Based Copolymers

The self-assembly of poly(ethyl glyoxylate)-poly(ethylene oxide)-poly(ethyl glyoxylate) (PEtG-PEO-PEtG) triblock copolymers in aqueous environments was systematically studied by using rheology and small-angle neutron scattering (SANS). These systems form associative micellar gels in water, with the PEtG end-blocks forming micelle cores and the PEO mid-blocks forming loops in the micelle coronas and intermicellar bridges. As PEtG block length is increased, rheology shows slower relaxation behavior, consistent with a longer lifetime of intermicellar bridges and associations. The length of the self-immolative PEtG block can be used to tailor the mechanical properties, size of nanoscale hydrophobic domains, and larger-scale assembly behavior of the block copolymer gels. These results can guide the design of self-immolative block copolymers with desirable rheological properties and nanoscale structures for a variety of applications.