Hetero‐Functional Polymers with Alternating Hydroxyl and Epoxy Groups Synthesized by Thiol‐yne Click (co)Polymerization

Abstract

A new family of hetero‐functional polythioethers with alternating hydroxyl and epoxy groups are facilely synthesized via photo‐initiated thiol‐yne click (co)polymerization under mild reaction conditions. Their chemical structures and hetero‐functional group density can be finely tuned by adjusting the feeding mole ratios. As the evidence of nuclear magnetic resonance and gel permeation chromatography tests shows, either the molecular weight or the hetero‐functional group density depend greatly on the SH bond cleavage energy of dithiols which can be predicted by theoretical calculation, using the density functional theory (DFT) with B3LYP hybrid functional and the QCISD methods. This paper provides access to a wide range of new materials with a specific structure and plentiful alternating hetero‐functional groups. Moreover, it unveils and highlights the role of SH bond cleavage energy of dithiols during the process of step‐growth thiol‐yne click (co)polymerization.

Effect of the topology on the antibacterial activity of cationic polythioether synthesized by all‐click chemistry

“…As shown in Figure 5, the T g values of L-CPTEs, M-CPTEs, and H-CPTEs were 10.9, 6.5, and −5.9 C, respectively, which were obviously higher than those of nonionic analogues. [35][36][37] The T g value of the H-CPTEs was slightly higher than those of the M-CPTEs and L-CPTEs, which seems contrary to the general conclusion of those nonionic analogues. Within the as-prepared CPTEs, the strong electrostatic interaction between anion and cation made the chain be stretching and stiff, leading to the higher T g values (about 30 C).…”

“…As shown in Figure S1, the proton signals at 2.64, 2.82, and 3.19 ppm were ascribed to epoxy group. [36,37] The signals of vinyl group at 5.12, 5.23, and 5.83 ppm were disappeared completely after 10 hr UV-irradiation. [38] After the thiolene addition, new peaks at 1.85, 2.65, and 3.12 ppm were clearly observed.…”

“…In recent years, the thiol-ene/thiolyne polymerization is reported that it is extremely suitable to prepare the polythioethers containing diverse functional groups due to the merits of fast reaction, high yield, and good tolerance for various functional groups. [31][32][33][34][35][36][37] In this work, UV-initiated thiol-ene and subsequent epoxy-amine click additions were facilely employed to fabricate the cationic polythioethers (CPTEs) with different degree of branching (DB) values of the hyperbranched topologies. These CPTEs allowed for further investigating the effect of different topologies on the antibacterial activity against Staphylococcus aureus and Escherichia coli.…”

Computational Study on Radical-Mediated Thiol-Epoxy Reactions

“…In our study, epoxies with different chemical environments based on these structures (Table ) were selected, and their reaction kinetics were investigated. To our knowledge, there are many computational evaluations of the structure–reactivity of thiol–ene reactions − and other specific thioether-forming reactions. − However, there is no quantum chemical study explaining the reaction mechanism of thiol–epoxy systems. Within the scope of this study, we presented the computational approximation for the radical mechanism of epoxy ring-opening polymerization, which explains the reasons for side reactions to enable future experimental studies.…”