Exceptional enhancement of ductility and toughness in poly(vinylidene fluoride)/carbon nanotubes composites

Abstract

The reinforcement of mechanical properties of polymeric materials is often important for widening their applications; however, it remains a technical challenge to effectively increase toughness without degrading stiffness and strength of the polymers. In this work, by a facile methodology combining solution mixing and melt blending, poly(vinylidene fluoride)/multi‐walled carbon nanotubes (PVDF/MWCNTs) composite with exceptionally enhanced ductility and toughness are prepared. With only 0.2 wt % CNT loading, the elongation at break has increased from originally 138% to almost 500%, while toughness improved by as much as 386%, without compromising the stiffness and strength. Note that raw CNTs are directly dispersed in the matrix without any surface modification. In order to elucidate this novel enhancement of ductility of PVDF/MWCNTs composites, we carried out detailed analyses based on results from ultra‐small‐angle X‐ray scattering (USAXS), cryo‐fractured surface morphology, differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). It is proposed that the enhanced ductility are contributed by a synergistic combination of “void pinning effect” of CNT, as well as the formation of γ phase polymorph as the interphase in the PVDF/CNTs composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43610.

Poly(vinylidene fluoride)–polyacrylonitrile blend flat‐sheet membranes reinforced with carbon nanotubes for wastewater treatment

“…However, the values for M3 and M4 with 1.5 wt % CNTs (Table S1, Supporting Information) were greatly reduced by an overabundance of CNTs in the membrane. This could be explained by aggregation of excess CNT particles between the PVDF and the PAN molecules, which caused local stress concentration and resulted in the deterioration of the membranes ductility. In addition, the effect of the CNTs on the stiffness of membranes exceeded the effect of intermolecular covalent bonds and also contributed to the decrease in the elongation.…”

“…There have been several studies on the effects of carbon nanotube (CNT) particles on the properties of PVDF and PAN membranes. For instance, Chen et al . reported that with only a 0.2% CNT loading, the ductility and toughness of the resulting PVDF membranes were greatly improved.…”

Salt Template Assisted BN Scaffold Fabrication toward Highly Thermally Conductive Epoxy Composites

“…PVDF has three commonly observed phases, namely, α, β, and γ phases. The α phase is the most thermodynamically stable with trans–gauche–trans–gauche chain conformation while the β phase is piezoelectric with an all-trans chain conformation; the γ phase is the transition state between α and β . According to the FTIR shown in Figure a, α (976 cm –1 ) and γ (833 cm –1 ) were observed in a neat PVDF scaffold without BN.…”

Dramatic Toughness Enhancement of Polydicyclopentadiene Composites by Incorporating Low Amounts of Vinyl-Functionalized SiO2

“…In general, the fracture morphology of a composite is important because it correlates with the mechanical properties and many other physical properties. 39 To investigate the dispersibility of V-SiO 2 in PDCPD, the freeze-fractured surfaces of PDCPD/V-SiO 2 composites were observed, and the results are shown in Figure 5. On the whole, V-SiO 2 was uniformly dispersed in all of the prepared samples (Figure 5a,b).…”