- Hydrolyzable polyureas bearing hindered urea bonds
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Hydrolyzable polymers are widely used materials that have found numerous applications in biomedical, agricultural, plastic, and packaging industrials. They usually contain ester and other hydrolyzable bonds, such as anhydride, acetal, ketal, or imine, in their backbone structures. Here, we report the first design of hydrolyzable polyureas bearing dynamic hindered urea bonds (HUBs) that can reversibly dissociate to bulky amines and isocyanates, the latter of which can be further hydrolyzed by water, driving the equilibrium to facilitate the degradation of polyureas. Polyureas bearing 1-tert-butyl-1-ethylurea bonds that show high dynamicity (high bond dissociation rate), in the form of either linear polymers or cross-linked gels, can be completely degraded by water under mild conditions. Given the simplicity and low cost for the production of polyureas by simply mixing multifunctional bulky amines and isocyanates, the versatility of the structures, and the tunability of the degradation profiles of HUB-bearing polyureas, these materials are potentially of very broad applications.
- Ying, Hanze,Cheng, Jianjun
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supporting information
p. 16974 - 16977
(2015/02/02)
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- Associative monomers
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Novel mono- and multi-functional non-ionic urethane monomers are prepared from surfactants comprising poly(ethylene oxide)(butylene oxide) copolymers, preferably C1 -C4 alkoxy-terminated, monohydric, ethylene oxide/butylene oxide block polymers and monoethylenically unsaturated aliphatic isocyanates. When polymerized with, e.g. acrylic acid or alkyl acrylates, these monomers provide copolymers exhibiting greatly enhanced thickening efficiency.
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