writer：Dan Xu, Ting Xu, Guorong Gao, Ying Xiao,Rong Wang*, Jingbo Yin* and Jun Fu*
keywords：Hydrogels, Machanical properties, solvent-polymer interactions
source：期刊
specific source：Journal of Polymer Science Part B Polymer Physics 2019, 57, 473-483
Issue time：2019年
Previous studies on hydrogels crosslinked by acrylated PEO99–PPO65–PEO99 triblock copolymer (F127DA) micelles demonstrate outstanding strength and toughness, which is attributed to the efficient energy dissipation through the hydrophobic association in the micelles. The current study further focuses on how the solvent property affects the structures and the mechanical properties of F127DA micelle crosslinked polyacrylamide gels. Binary solvents comprised of dimethyl sulfoxide (DMSO) and water are used to adjust the polymer/solvent interactions, which consequently tune the conformations of the polymer chains in the network. The presence of DMSO significantly decreases the strength but increased the stretchability of the gels, whereas the overall tensile toughness remained unchanged. In situ small‐angle X‐ray scattering measurements reveal the deformation of micelles along with the stretching direction. A structure evolution mechanism upon solvent change is proposed, according to the experimental observations, to explain influence of solvent quality on the mechanical properties of the micelle‐crosslinked gels.