Mechanochemical generation of acid-degradable poly(enol ether)s

Abstract

A mechanically responsive polymer system that is hydrolytically stable without stress, but unmasks enol ether backbone linkages under force to allow facile hydrolytic degradation.

Metal-Catalyzed Switching Degradation of Vinyl Polymers via Introduction of an “In-Chain” Carbon–Halogen Bond as the Trigger

“…On the other hand, the development of sustainable polymer materials that can be recycled or disposed without putting a burden on earth is highly required, as the environmental impact of the polymer waste has become more and more serious. − For the global issue, a concept of “switching degradation” has attracted attention for the polymer design, because it could allow on-demand degradation after use while the material stability is ensured. Some researchers have recently reported on switching from “stable use” to “degradation” or “depolymerization” under some stimuli, − and the key is an introduction of the “trigger” into the polymer chain.…”

Heterocyclic Mechanophores in Polymer Mechanochemistry

“…When the cyclic-ether-fused bicyclohexene mechanophore is embedded into a polymer backbone, it is Cluster Account Synlett transformed into enol ether, which is easily hydrolyzed under mildly acidic conditions. 119 The common feature of all these systems is that they rely on homocyclic mechanophores, cyclobutane or cyclobutene, which should be designed to bear preprogrammed hydrolyzable functionalities, and treatment of acid or base is required to accomplish the degradation of polymers.…”

Synthesis of degradable and chemically recyclable polymers using 4,4-disubstituted five-membered cyclic ketene hemiacetal ester (CKHE) monomers

“…Degradable polymers nd numerous applications in, e.g., drug delivery, packaging, and agriculture elds. [1][2][3][4][5][6][7][8][9] In the eld of radical polymerization, degradable polymers are prepared via radical ring-opening polymerization of cyclic ketene acetals (CKAs), [10][11][12][13][14] for example, gaining signicant attention. Examples of CKA are 2-methylene-1,3-dioxepane (MDO), [15][16][17][18][19][20][21][22][23] 5,6-benzo-2methylene-1,3-dioxepane (BMDO), [24][25][26] and 2-methylene-4phenyl-1,3-dioxolane (MPDL) [27][28][29][30] (Scheme 1).…”