Dual cross-linking strategy to prepare fluorine-containing poly(arylene ether nitrile) films with a low dielectric constant and ultra-low water uptake. Issue 44 (24th October 2022)

• Record Type: Journal Article
• Authors: Cao, Tong; Shi, Yifei; Li, Xiaoyu; Peng, Jun; Liu, Xiaobo; Huang, Yumin
• Is Part Of: Polymer chemistry. Volume 13:Issue 44(2022)
• Page Start: 6213
• Page End: 6222
• Publication Date: 2022-10-24
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d2py01146h
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Dual cross-linked networks based on fluorine-containing poly(arylene ether nitrile) were constructed by a simple thermal treatment for obtaining flexible low-dielectric materials with excellent comprehensive performance. Abstract : A low k -value in a humid environment is an important parameter for low dielectric materials, as the k -value is very sensitive to humidity. In order to obtain a low dielectric constant and improve water resistance, a series of poly(arylene ether nitrile) copolymers containing trifluoromethyl groups and two cross-linking sites of cyano and propenyl groups (D n AF-PEN) were designed and synthesized. The presence of the propenyl groups synergistically promotes the cross-linking of cyano groups; so dual cross-linked networks were constructed by a simple thermal treatment. With the change of the content of the cross-linkable group and cross-linking temperature, the properties of D n AF-PEN can be well tuned. The presence of the dual cross-linked networks and the introduction of trifluoromethyl allowed the films to exhibit excellent thermal and mechanical properties, a low dielectric constant ( k = 2.26–2.43 at 1 MHz), hydrophobic surface (104.9–111.2°) and ultra-low water uptake (≤0.28%). Moreover, the k -value of the films remains stable for a long time in a humid environment. Furthermore, the cross-linked films were used to prepare flexible copper-clad laminates, which showed the highest peel strength of up to 6.64 N cm −1 . The excellent comprehensive properties make the cross-linked films excellent dielectric materials in both dry and humid environments.