Mechanical, Thermal Stability, and Flame Retarding Properties of Phosphorus-Modified PET Blended with DOPO-POSS

Abstract

In this study, an antidroplet flame retardant system based on FRPET (phosphorus-containing copolyester) is constructed with DOPO-POSS (polyhedral oligomeric silsesquioxane containing DOPO) as an additive flame retardant. It is demonstrated that DOPO-POSS has good dispersibility at a lower amount. When the amount of DOPO-POSS is 9 wt %, the residual char of DOPO-POSS/FRPET at 700 °C increases to 23.56 from 18.16% of FRPET, and the maximum thermal weight loss rate also reduces. What is more is that the limiting oxygen index increases to 33 from 26% of FRPET. The flame burning time is shortened to 4.95 from 20.8 s, the phenomenon of self-extinguishing of the fire occurs, and the vertical combustion level is increased from V-2 to V-0. Compared with FRPET, the peak of the heat release rate decreases by 66.0%, the total heat release decreases by 32.4%, the flame retardancy index (FRI) reaches an excellent value, and the condensed-phase products significantly improve. The Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy−energy dispersive X-ray spectrometry (SEM−EDX), thermogravimetric−FTIR (TG−FTIR), and pyrolysis−gas chromatograph/mass spectrometry (Py−GC/MS) results indicate that DOPO-POSS contributes to the formation of char layers and decomposes to generate free radicals with a quenching effect. In a word, DOPO-POSS is an effective radical trapper and charring agent for PET and exerts a flame retardancy effect in gaseous and condensed phases simultaneously.

Preparation and smoke suppression mechanism of flame‐retardant PBS composites with BNNS@DOPA

“…By analytical fitting, the P2p XPS of 3%BNNS@DOPA/PBS (Figure 10c) has two fitted peaks at 133.4 and 134.7 eV, representing OPO and PO 3 , primarily originating from metaphosphoric and phosphoric acids. The decomposition of the DOPO chain segment produces phosphoric acid 38 . Compounds like metaphosphoric acid coat the PBS surface, facilitating matrix dehydration for carbon formation.…”

Synthesis and Characterization of a Novel DOPO-Based Flame Retardant Intermediate and Its Flame Retardancy as a Polystyrene Intrinsic Flame Retardant

“…FTIR and SEM analysis of PS 148 -Br and PS- b -PFAA-DOPO after combustion showed that the FAA-DOPO block was introduced into the polystyrene macromolecular chain; during the combustion of PS- b -PFAA-DOPO, the DOPO groups degrade to produce phosphoric acid and polyphosphoric acid, which can accelerate the dehydration of polystyrene and promote the carbonization behavior of polystyrene. Meanwhile, the PO· and PO 2 · radicals produced by the combustion of DOPO groups capture the flame propagating radicals (H· and HO·) to achieve the purpose of flame retardant. ,,,,,− …”

Silicone rubber/benzoxazine resin‐based nanocomposites: A study on compatibility and thermal stability

“…This material can be chemically or physically blended with the polymer matrix 38,39 . In recent years, the incorporation of POSS into the rubber and thermosetting polymers has been reported by some researchers 11,40–42 . Zhao, et al reported chemically incorporating 2.5% phenyl‐vinyl‐POSS into polydimethylsiloxane (PDMS), which ameliorated the tensile strength from 0.2 to 0.27 MPa and elongation at break from 14% to 123.6%.…”

“…38,39 In recent years, the incorporation of POSS into the rubber and thermosetting polymers has been reported by some researchers. 11,[40][41][42] Zhao, et al reported chemically incorporating 2.5% phenyl-vinyl-POSS into polydimethylsiloxane (PDMS), which ameliorated the tensile strength from 0.2 to 0.27 MPa and elongation at break from 14% to 123.6%. Also, it was reported that the initial decomposition temperature of silicone rubber augmented from 344.1 to 344.4 C. 43 Thermal stability and curing kinetics of benzoxazine composites reinforced by POSS, carbon nanotubes (CNT), and clays have been investigated by Lin et al Their results showed that incorporating POSS into BZ resin hindered network formation and enhanced the thermal stability of BZ resin; however, the clay enhanced the rate of the crosslinking reaction of BZ resin, especially at the beginning and after the middle of the crosslinking process.…”