TY - DATA T1 - Dendronized Polymers with Ureidopyrimidinone Groups: An Efficient Strategy To Tailor Intermolecular Interactions, Rheology, and Fracture PY - 2017/06/19 AU - Leon F. Scherz AU - Salvatore Costanzo AU - Qian Huang AU - A. Dieter Schlüter AU - Dimitris Vlassopoulos UR - https://acs.figshare.com/articles/journal_contribution/Dendronized_Polymers_with_Ureidopyrimidinone_Groups_An_Efficient_Strategy_To_Tailor_Intermolecular_Interactions_Rheology_and_Fracture/5119822 DO - 10.1021/acs.macromol.7b00747.s001 L4 - https://ndownloader.figshare.com/files/8702116 KW - Nonlinear rheological measurements KW - shear strain KW - UPy content increases KW - generation numbers g KW - Tailor Intermolecular Interactions KW - transition N2 - A library of poly­(methyl methacrylate)-based dendronized polymers with generation numbers g = 1–3 was prepared, which contain different degrees of dendritic substitution (0–50%) with strongly hydrogen bonding 2-ureido-4­[1H]­pyrimidinone (UPy) moieties at their respective g = 1 levels. Our rheological and thermal studies demonstrate that the strong intermolecular UPy interactions are suppressed for g = 2 and essentially eliminated for g = 3. Focusing on samples with short backbone degrees of polymerization (Pn ≈ 40), the linear viscoelastic response alters from liquid-like in the absence of UPy to gel-like with ever increasing moduli as the UPy content increases. Nonlinear rheological measurements indicate a transition from ductile to brittle behavior and, in parallel, a transition from shear strain thinning to shear strain hardening. This unique behavior makes UPy-DPs promising candidates for the design of new functional materials. ER -