Thermal Stability, Pyrolysis Behavior, and Fire-Retardant Performance of Melamine Cyanurate@Poly(cyclotriphosphazene-co-4,4′-sulfonyl diphenol) Hybrid Nanosheet-Containing Polyamide 6 Composites

Abstract

A novel halogen-free highly cross-linked supramolecular poly(cyclotriphosphazene- co -4,4′-sulfonyl diphenol) (PZS)-functionalized melamine cyanurate (MCA) (MCA@PZS) hybrid nanosheet fire-retardant (FR) was synthesized and thoroughly characterized using scanning electron microscopy, Fourier-transform infrared (FTIR), X-ray diffraction, and X-ray photoelectron spectroscopy analyses. The polyamide 6 (PA6) composites comprising MCA, PZS, and the MCA@PZS hybrids were prepared via the melt-blending technique. The thermogravimetric analysis combined with FTIR and mass spectroscopy revealed that during thermal degradation, the PA6/MCA@PZS composites released less toxic gases and small organic volatile compounds than the neat PA6 and composites containing MCA or PZS solely. Moreover, compared to neat PA6, the PA6 composite with a 5 wt % MCA@PZS hybrid exhibited enhanced fire retardation properties, with a 29.4 and 32.1% decrease in the peak heat and total heat release rates, respectively. Besides, the PA6 composites with MCA@PZS-5% content achieved a V-0 rating in the UL-94 test. Finally, based on the obtained results from gaseous and condensed phases, the possible mechanism responsible for improved FR properties of the PA6/MCA@PZS composites was proposed.

Synthesis of a novel aluminium salt of nitrogen-containing alkylphosphinate with high char formation to flame retard acrylonitrile–butadiene–styrene

“…The AlNP was synthesized successfully and confirmed with FTIR, 1 H, 13 C and 31 P-NMR and XRF. AlNP was thermal stable and retained 56.1% of char residues at 700°C.…”

“…The 1 H, 13 C and 31 P nuclear magnetic resonance (NMR) spectra were performed in DMSO-d 6 at 25°C on a 400 MHz of Mercury VX-400 instrument (Varian, US). Tetramethyl silane was used as a reference of 1 H, 13 C and 85% H 3 PO 4 is used as a reference of 31 P-NMR spectra. Fourier transform infrared (FTIR) measurement royalsocietypublishing.org/journal/rsos R. Soc.…”

Preparation of piperazine cyanurate by hydrogen‐bonding self‐assembly reaction and its application in intumescent flame‐retardant polypropylene composites

“…The first stage occurs at around 170°C, which may be ascribed to the removal of moisture. The second decomposition stage occurs at temperature ranging from 279°C to 478°C, attributing to the decomposition of PA and triazine ring derivatives with the elimination of NH 3 . Moreover, the temperature at 5‐wt% mass loss of PCA is found at around 280°C.…”

“…Melamine cyanurate (MCA), a commercial flame retardant with planar network, is synthesized through hydrogen bonding supramolecular self‐assembly of melamine and cyanuric acid (CA) . PA is a kind of heterocyclic compound containing two nitrogen atoms, which shows an obvious flame‐retarding effect for its good thermostability, high nitrogen content, and high reactivity .…”

Thermal aging properties of flame retardant silicone rubber based on melamine cyanurate

“…As shown in spectra curve of surface and inner samples, 3239 and 3367 cm −1 were attributed to the symmetric and asymmetric absorption of the NH and NH 2 groups after forming hydrogen bond, respectively, while those at 1778 and 1729 cm −1 were corresponded to the free CO unit and the stretching vibration of associated CO, respectively. The peak at 1668 cm −1 was belonged to the CN group 35,36 . It was notable that the characteristic peaks of MCA on sample surface became disappeared as the aging process proceeded, suggesting the decomposition of the surface MCA during thermal aging process 37 (Figure 5(a)).…”