Side-Chain Architecture-Dependent Thermoresponsive Behaviors of Graft Polymers with Poly(N-isopropylacrylamide) Pendants
Fujin Duan，Gege Liu，Jinqian Zhang，Xin Zhao，Qingqing Wang，Youliang Zhao（赵优良）*
Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Key Laboratory of Polymeric Materials Design and Synthesis for Biomedical Function,Jiangsu Key Laboratory of Advanced Functional Polymer Materials, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
Macromolecules 2025, 58, 1594−1607
Abstract:The variations of side-chain architecture can significantly affect thethermoresponsive behaviors of graft polymers. This study is aimed at designing lineargraft polymers with linear or cyclic pendants (LGPLs/LGPCs) to elucidate the distinctthermostability of polymer solutions. Three pairs of poly(N-isopropylacrylamide)(PNIPAM)-bearing graft polymers with a weight-average graft number (Ng) up to 16are synthesized by the combination of the ring-first method, fractionation, and topologytransformation. The chain architecture and graft number can affect the thermostabilityand thermosensitivity of polymer aqueous solutions, in which thermo-induced maximalvariations of transmittance, light scattering intensity, and fluorescence intensity ratiorelated to amide−water hydrogen bonding drastically decrease with the incorporationof cyclic pendants and an increase of Ng. LGPLs with pronounced chain entanglementcan self-assemble into thermostable lamellae, while other polymer assemblies aresubjected to thermo-induced sphere-to-vesicle or vesicle-to-lamella transitions. Thisresearch affords a promising method to construct graft polymers with variable architectural parameters to achieve topology-dependent thermoresponsive behaviors.
Article information://doi.org/10.1021/acs.macromol.4c02611
