Flexible h-BN/fluorinated poly (arylene ether nitrile) fibrous composite film with low dielectric constant and high thermal conductivity fabricated via coaxial electrospinning hot-pressing technique

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2022-09, Vol.649, p.129455, Article 129455
• Main Authors: Yang, Wei, Zhan, Yingqing, Feng, Qingying, Sun, Ao, Dong, Hongyu
• Format: Article
• Language: English
• Subjects: Dielectric performance; Electrospinning; Hexagonal boron nitride; Polymer-matrix composite; Thermal conductivity
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2022.129455

The rapid development of electronics puts forward higher requirements on the low dielectric materials. Especially, the polymer-based dielectric film with low dielectric constant, high thermal conductivity, and heat-resistance is essential to the flexible electronics. However, the balance of these intended performance is still a big challenge. In this work, we reported the flexible poly (arylene ether nitrile) (PEN) fibrous composite film with low dielectric constant and high thermal conductivity by coaxial electrospinning hot-pressing technique. Interestingly, such bi-functional fibrous composite film was rationally designed by using hexagonal boron nitride (h-BN)/fluorinated PEN (PEN-F) as shell layer and polyvinylpyrrolidone (PVP) as the core layer of fibers, which could further form the porous, hollow, and balsam pear-shaped structure after the hot-pressing and dissolution process. Owing to introduction of the h-BN nanosheets, intrinsic fluorine groups of PEN-F, and hollow nanofiber structure, the dielectric constant and dielectric loss of fibrous composite film could be as low as 1.74 and 0.0092 at 1 kHz, respectively. Furthermore, the in-plane thermal conductivity of fibrous composite film could reach 0.811 W m−1 K−1 by incorporation of 7 wt% h-BN. In addition, the fibrous composite film exhibited high thermal stability (T5 % = 498 °C and Tg = 182 °C) and mechanical strength (Tensile strength = 39.2 MPa and tensile modulus = 250.9 MPa). Therefore, this work opens up an alternative method to prepare high-performance polymer composite film with low dielectric constant and high thermal conductivity, which suggests the broad application in the future flexible electronics. [Display omitted] •The hollow and balsam pear-shaped PEN/h-BN fibrous composite film was prepared.•The dielectric constant and loss of film was as low as 1.74 and 0.0092, respectively.•The in-plane thermal conductivity could reach 0.811 W m−1 K−1.•The film exhibited high thermal stability and mechanical strength.