Designing improved electromagnetic shielding efficacy of poly(3‐hydroxybutyrate‐co‐3hydroxyvalerate) nanocomposites foam using carbon nanotubes and graphene nanoplatelets

Abstract

AbstractNowadays, one of the design direction of bio‐derived and biodegradable polymer foams with multi‐functionalization is how to attain superior electromagnetic interference (EMI) shielding property, which has become a hot topic. Herein, bio‐based poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) foams filled with carbon nanotubes (CNTs) and/or graphene nanoplatelets (GNPs) were fabricated by supercritical carbon dioxide. As observed by optical microscope and scanning electron microscope, the CNTs and GNPs in PHBV matrix might gradually construct three kinds of network structures (CNTs‐CNTs, GNPs‐GNPs and GNPs‐CNTs network structures), which would improve the melt viscoelasticity, crystallization, electrical, dielectric and EMI shielding properties of PHBV. The complex viscosity and storage modulus of PHBV nanocomposites with the ratio of CNTs/GNPs as 1:1 rose nearly three orders of magnitudes than those of pure PHBV, in addition, its crystallization temperature and crystallinity increased remarkably to 122°C and 62%, individually. When the CNTs/GNPs ratio was 1:1 at a low total content of 3 wt%, PHBV nanocomposite and its foam implemented the high dielectric properties. Furthermore, the EMI specific shielding effectiveness of obtained PHBV was blend with 1.5 wt% CNTs and 1.5 wt% GNPs nanocomposite foam was the highest, reaching 19.3 dB cm3/g. This work paved a feasible way to the production of eco‐friendly PHBV nanocomposite foams for the application of electronics and aerospace industries.Highlights PHBV/CNTs/GNPs foams were prepared using a scCO2‐assisted foaming method. Dispersion of carbon fillers in PHBV was the best as CNTs/GNPs ratio was 1:1. G' of PHBV/C1.5/G1.5 specimens were increased by three orders of magnitude. EMI specific shielding effectiveness of PHBV/C1.5/G1.5 nanocomposite foam could reach 19.3 dB cm3/g.