Degradable Poly(lactic acid)/Metal–Organic Framework Nanocomposites Exhibiting Good Mechanical, Flame Retardant, and Dielectric Properties for the Fabrication of Disposable Electronics

Abstract

Nano metal–organic frameworks (ZIF-8) particles were synthesized, and poly­(lactic acid) (PLA)/ZIF-8 nanocomposite films were prepared by solution-blending and film-casting methods. The addition of nano ZIF-8 particles improved the mechanical properties and had an impact on the crystallization of PLA. The electrical properties of the PLA/ZIF-8 nanocomposites were found to be dependent on the frequency and the ZIF-8 content. The prepared PLA/ZIF-8 films had good transparency even as the content of the nano ZIF-8 particles reached 3 wt %. Compared with 21.5% of pure PLA, the limited oxygen index value of the nanocomposite film containing 1 wt % ZIF-8 reached 26.0%. Therefore, it is proposed that the prepared nanocomposites can be used as the substrates and dielectric to make disposable electronics. The char residues after burning were studied in detail by scanning electron microscopy and Raman and X-ray photoelectron spectroscopies, and the flame retardant mechanism was also discussed.

Zeolitic imidazolate frameworks‐8 modified graphene as a green flame retardant for reducing the fire risk of epoxy resin

“…For the ZIF‐8/EP composite, its PHRR and THR are 395 kw/m 2 and 30.8 MJ/m 2 , respectively, a decrease by 57 and 25.2% in comparison with pure EP, respectively. This may be attributed to the formation of nonflammable gases during the decomposition of organic ligand in ZIF‐8, which could dilute flammable gas and inhibit the combustion of EP composites . Meanwhile, the metal oxide generated in the combustion of the ZIF‐8/EP composites possesses a catalytic charring effect which could effectively improve the thermal stability of char residue .…”

“…At present, some researchers have tried to apply MOFs materials in the field of flame retardancy. Shi et al found that when 3 wt% ZIF‐8 was added into poly(lactic acid) (PLA), the LOI value of PLA/ZIF‐8 composites reached 26%, an increase by 5.5% in comparison with that of pure PLA, and its flame retardancy was improved . Hou et al found that, when 2 wt% Co‐MOF was added into PS, compared with pure PS, the PHRR and THR of the PS/Co‐MOF composites were decreased by 28.0% and 17.6%, and their flame retardancy was improved to some extent …”

Improving the flame retardancy of polypropylene by nano metal–organic frameworks and bioethanol coproduct

“…In contrast, the char residue of PP‐5 contains element Zn, and the surface of the char residue is very smooth and compact as shown in Figures B and D. This shows that ZIF‐8 can effectively improve the structure of char layer, which is due to the facts that the Zn 2+ or ZnO from ZIF‐8 can capture macro radicals allowing recombination and leading to intermolecular crosslinking …”

“…The mixture was magnetically stirred at room temperature for 1 hour. The resultant particles were centrifuged, washed with CH 3 OH, and then dried in an oven at 80°C …”

Synthesis of a novel polyphosphazene/triazine bi‐group flame retardant in situ doping nano zinc oxide and its application in poly (lactic acid) resin

“…In recent years, many researches about flame‐retardant PLA materials have been proposed . Among them, the most efficient flame‐retardant system for PLA is the combination of APP and the bio‐based charring agent such as lignin, starch, and β‐cyclodextrin (CD) .…”