Bioderived and Biodegradable Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Nanocomposites Based on Carbon Nanotubes: Microstructure Observation and EMI Shielding Property Improvement

Abstract

In view of the exhaustion of nonrenewable oil-based resources and the concerns on the environmental issues triggered by nondegradable plastics, biobased and biodegradable polymers have aroused increasing interest in recent decades. In this paper, bionanocomposites composed of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) as a matrix and carbon nanotubes (CNTs) as nanofillers were fabricated via a facile, green, and efficient method. Interconnected CNT structures and CNT−CNT networks formed in PHBV/CNT nanocomposites were demonstrated by a scanning electron microscope and transmission electron microscope. Compared with those of neat PHBV, the crystallization temperature and crystallinity of PHBV/CNT nanocomposites increased remarkably; in addition, the storage modulus increased by 6 orders of magnitude. A low electrical percolation threshold of 0.66 wt % was achieved in the PHBV/CNT nanocomposite. Furthermore, the dielectric and electromagnetic interference (EMI) shielding properties of PHBV/CNT nanocomposites were significantly improved with the increase of CNT content. For a typical PHBV/CNT sample with a thickness of 3 mm, the EMI shielding effectiveness reached 43.5 dB. The environmentally friendly PHBV/CNT nanocomposites prepared in this study were not only endowed with multifunctionality by the inclusion of CNTs but also made full use of the biogenetic derivation and biodegradability of the matrix to replace petroleum-based plastics and alleviate environmental pollution.

Synthetic Celluloses as Green Fillers for the Enhancement of the Crystallization and Mechanical Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

“…Due to fewer nucleation sites, the spherulites in neat P­(HB- co -HV) have more space to grow until they collide with each other. Therefore, the quantity of spherulites is small, and the size of spherulites is large (about 370.3 μm as shown in Figure a), which is why neat P­(HB- co -HV) is brittle. , After the addition of SC, the number of spherulites increases significantly, and the size of spherulites decreases obviously, indicating that SC has an effective nucleation effect on P­(HB- co -HV) (about 174.5 μm as shown in Figure b). This is also consistent with the above-mentioned DSC results.…”

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

“…13,14 In recent years, the improvement of EMI shielding properties of polymer nanocomposites with single carbon nanofillers have been widely explored. 15,16 Shi et al 15 proposed a novel three-dimensional printing approach to fabricate poly(lactic acid)/10 wt%-graphene nanoplatelets (GNPs) nanocomposites, which possessed admirable electrical and EMI shielding properties of 34.7 dB. In our previous works, 16 5 wt% of carbon nanotubes (CNTs) were meltmixed into PHBV and the EMI shielding effectiveness of resultant nanocomposites reached 43.5 dB.…”

“…15,16 Shi et al 15 proposed a novel three-dimensional printing approach to fabricate poly(lactic acid)/10 wt%-graphene nanoplatelets (GNPs) nanocomposites, which possessed admirable electrical and EMI shielding properties of 34.7 dB. In our previous works, 16 5 wt% of carbon nanotubes (CNTs) were meltmixed into PHBV and the EMI shielding effectiveness of resultant nanocomposites reached 43.5 dB. Although the high loading of carbon nanofillers facilitated the generation of efficient conductive network structures, the undesired agglomeration might simultaneously occur, which might limit the electrical and EMI shielding properties of polymer nanocomposites.…”

“…In our previous works, CNTs or GNPs were introduced into PHBV matrix to obtain favorable EMI shielding properties. 16,24 Based on our previous studies stated above, it should be a beneficial and interesting attempt to prepare PHBV nanocomposites or their foams with desired EMI shielding properties by adding CNTs and GNPs concurrently. To our knowledge, researches on the EMI shielding properties of scCO 2 -assisted PHBV/ CNTs/GNPs nanocomposite foams have scarcely been published and the facile method suggested in this manuscript was supposed to fill the vacancy.…”

Self-Healing Nanocomposites with Carbon Nanotube/Graphene/Fe3O4 Nanoparticle Tricontinuous Networks for Electromagnetic Radiation Shielding

“…In addition, reflected electromagnetic waves may cause secondary environmental hazards. High-performance polymer composites consisting of conductive fillers inserted into the polymeric matrix have attracted attention as potential new-generation EMI systems because of their advantages of being lightweight and having good processability, high environmental stability, and low cost. − Recently, it has become a further trend to introduce external field response materials regarding temperature, light, space-time, wind, and other fields into electromagnetic shielding systems to meet the diverse needs of the environments. Among them, self-healing ability, which involves simultaneous transformation between time and the material structure, is an important function in the field of space-time .…”