Novel flame retardant zirconia-reinforced nanocomposites containing chlorinated poly(amide-imide): synthesis and morphology probe

Abstract

In the present investigation, a thermally stable poly(amide-imide) (PAI) was synthesised from the polymerisation reaction of 4,4 0 -methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) as a chlorinated diacid with 4,4 0 -methylenebis (3-chloro-2,6-diethylaniline) using molten tetra-n-butylammonium bromide and triphenyl phosphite as a condensing agent and green media. This methodology offers enhancements for the synthesis of polymers with regard to yield of products, simplicity in operation, and green aspects by avoiding volatile solvents. From the chemical point of view, the chloride and ethylene groups impart to the polymer's chain increased solubility of obtained polymer in organic solvent. Then, the surface of zirconia nanoparticles (ZrO 2 -NPs) was modified with 3-aminopropyltriethoxylsilane as a coupling agent. The obtained polymer and inorganic metal oxide NPs were used to prepare PAI/ZrO 2 nanocomposites through ultrasonic irradiation. The formation of PAI was confirmed by 1 H-NMR, FT-IR spectroscopy, and elemental analysis. The obtained polymer was synthesised with good yield (90%) and moderate inherent viscosity (0.48 dL/g). The resulting NP filled composites were also characterised by FT-IR, XRD, FE-SEM, TEM and TGA. The TEM and FE-SEM results indicated a high dispersion level of the nanoscale inorganic particles in the polymer matrix. In this article, ZrO 2 -NPs are employed to improve flame retardancy of nanocomposites. TGA thermographs confirmed that the heat stability of the prepared NP-reinforced composites was improved in the presence of ZrO 2 nanocrystals.

A simple and environmentally friendly method for surface modification of ZrO2 nanoparticles by biosafe citric acid as well as ascorbic acid (vitamin C) and its application for the preparation of poly(vinyl chloride) nanocomposite films

“…a). These characteristic peaks correspond to highly crystalline monoclinic structure that is in agreement with previous reports . Because of the low concentration of modifiers, their characterization peaks in XRD analysis of modified NPs were not observed.…”

“…The cause of absorbance in visible region (400–800 nm) for ZrO 2 is O 2− (2p) → Zr 4+ (A 1g ) charge transfer related to the excitation of electrons from the valence band to the conduction band. Since the configuration of Zr 4+ ions is d 0 , no d–d transitions were observed in the vision region .…”

Enhancing the material performance of chloroprene rubber (CR) by strategic incorporation of zirconia

“…The halogenated polymers like CR usually show flame resistance as it provides hydrogen halides which can serve as very good radical scavengers for • H and • OH radicals. 36 We have theoretically studied the flame retardancy of the synthesised composites by calculating char yield and LOI (Limiting oxygen index) values [43][44][45] (Table 3). The char yield of the filled composites increases from 32% (unfilled compound) to 37-45 %.…”

The synthesis of poly(vinyl chloride) nanocomposite films containing ZrO2 nanoparticles modified with vitamin B1 with the aim of improving the mechanical, thermal and optical properties

“…The monoclinic crystalline structure of ZrO 2 has two direct interband transitions at 5.93 and 5.17 eV. The pure ZrO 2 NPs have a sharp and intense band at 212 nm with an absorption edge around 300 nm [ 23, 24 ]. For the pure PVC, the absorbance spectrum showed absorbance peaks at λ = 210 and 280 nm, which can be assigned to the π–π* and n–π* transition, respectively.…”