This work presents a strategy for fabricating low dielectric epoxy copolymers through copolymerizing bisphenol A diglycidyl ether with N,N′-disilyl bis(secondary amine)s, a series of difunctional silylamines synthesized by silylation of bis(secondary amine)s. A study on the model reaction of monoepoxy with monofunctional silylamines identified that the reaction proceeded smoothly in tetrahydrofuran with Mg(ClO 4 ) 2 catalysis and mechanistically through sequential silylamine-induced epoxy ringopening and silylotropic N → O migration, a process with favorable Gibbs free energy changes as confirmed by density functional theory calculations. The copolymers demonstrated remarkably low dielectric constants and dielectric losses due to the formation of the low-polarizable silyloxyl instead of the hydroxyl group in polymerization and the enlarged molecular free volume. In addition, the copolymers showed desirable toughness, hydrophobicity, and thermal stability. As a tool to achieve these desirable features, the strategy developed in this work may find promising application in designing low dielectric epoxy resin materials for use in the microelectronic field.
Urushiol is a resource-limited natural coating material with diverse applications; however, the synthesis of urushiol analogues and the realization of their urushiol-like performance remain challenging. Herein, four urushiol analogues, namely, 3-((4-alkenoylpiperazin-1-yl)methyl)catechols with the precise 3-substitution pattern on a catechol as that found in urushiol were synthesized by employing the Mannich reaction of catechol with formaldehyde and N-Boc-piperazine as the key step in a two-step route. By using optimization, the advantages of convenience in operation, cost-effectiveness, and scalability could be obtained. The electropolymerization of these analogues on copper was found to be practical due to their higher aerobic stability than urushiol, affording robust coatings with desirable hardness, adhesion strength, hydrophobicity, and thermal stability. Furthermore, the coatings exhibited effective corrosion protection on copper with initial anticorrosion efficiency up to 99.9% and comparatively higher efficiency (more than 97%) after 4 weeks of immersion in 3.5 wt% NaCl solution. The evidence from the electrochemical and infrared spectroscopic characterization data revealed that the electropolymerization process mechanically involved the free radical coupling of phenoxyl radicals to themselves and to the C]C bonds in the side chain, forming a robust crosslinking coating. This work paves a way for the synthesis of high-performance urushiol analogues with potential applications as metal protection materials.Scheme 1 Composition of natural urushiol, structures of synthesized urushiol and urushiol analogues, and synthesis route for urushiol analogues used in this work.This journal is
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.