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Melamine‐formaldehyde (MF) foam, while intrinsically flame retardant, necessitates further refinement to meet stringent fire safety standards, particularly in terms of heat release rate and thermal stability. In this study, an innovative approach was adopted wherein an inorganic substance, potassium water glass (WG), was employed to create an encapsulation layer on the surface of the MF foam structure via a straightforward dip‐coating technique. The composite foam underwent a comprehensive analysis of its structure and flame retardant characteristics, using test evaluations such as micro‐scale combustion calorimeter (MCC) testing, cone calorimeter testing (CCT), and thermogravimetric‐Fourier infrared spectrometer (TG‐IR) assessments. It was found that the even coating of WG on the MF foam surface profoundly enhanced the foam's structural integrity. Utilizing the shielding properties of this inorganic layer, the hybrid foam's thermal stability experiences a remarkable augmentation. The peak of heat release rate (pHRR) and the total heat release rate (THR) of the MF foam experienced an impressive reduction of 85.2% and 78.8%, correspondingly. Notably, this advancement is concomitant with a substantial decrease of 39.2% in the total smoke release (TSR) and a notable amelioration in mechanical characteristics. Such developments undeniably broaden their application horizons across diverse domains. [ABSTRACT FROM AUTHOR]

• AMPAP-NH 4 + is synthesized through a one-pot method, avoiding the need for organic solvents or halogens in the process. • AMPAP-NH 4 + could engage in chemical reactions with cellulose, resulting in the formation of stable P O C bonds. • According to the TL848-2017 testing standard, the finished wood pulp paper demonstrates excellent durable flame retardancy. Wood pulp paper (WPP) is an exemplary substrate material, yet its flammability impedes the widespread application in diverse functional fields. Herein, a highly effective, colorless and transparent phosphorus–nitrogen flame retardant, namely ammonium salt of tris(hydroxymethyl)aminomethane diphosphonic acid (AMPAP-NH 4 +) without halogen and formaldehyde, has been synthesized for WPP. Chemical grafting was employed to confer highly durable flame retardancy to the WPP, enabling it to maintain excellent fire resistance after functionalization. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analysis demonstrated that AMPAP-NH 4 + was directly linked to cellulose fibers via P O C bonds, effectively introducing P and N elements into the WPP without altering the surface morphology of the fibers. Results from thermogravimetric analysis, vertical burning test, limiting oxygen index test, cone calorimeter test and thermogravimetric-Fourier infrared spectrometer test demonstrated that the treated WPP exhibited outstanding flame retardancy. The peak heat release rate (pHRR) and total heat release (THR) values decreased by 80.8% and 70.9%, respectively, and the limiting oxygen index (LOI) increased to 41.4%. Furthermore, due to the stability of the P O C bond, the treated samples remained unignited after 168 h, with a high LOI value of 35.3%. In summary, AMPAP-NH 4 + serves as a phosphorus–nitrogen synergistic transparent flame retardant that can effectively and durably impart paper with flame retardancy without altering its surface morphology. [Display omitted] [ABSTRACT FROM AUTHOR]

With the development of microelectronics and flexible wearable electronic devices, poly(vinyl alcohol) (PVA) based thermal interface materials (TIMs) have received much attention. However, poor heat dissipation and high flammability have emerged as the key issues that restrict their application. In this work, the directional alignment of phytic acid (PA) modified boron nitride nanosheets (BNNS) and Ti 3 C 2 T x MXene in PVA matrix was achieved by ice-templated assembly, which simultaneously enhanced the flame retardancy and thermal conductivity of PVA composite films (PVA/BT x). Owing to the synergistic effect between oriented BNNS and Ti 3 C 2 T x MXene on forming the thermally conductive network within PVA matrix, the in-plane thermal conductivity of PVA/BT x -30 composite film was increased to 8.54 W m−1 K−1, much higher than that of PVA film (0.30 W m−1 K−1). Meanwhile, the heat dissipation process of PVA films applied as TIMs was simulated, which showed that PVA/BT x -30 films exhibited excellent thermal conduction and significantly decreased the operation temperature of electronic devices. Additionally, the peak heat release rate (PHRR) and total heat release (THR) of PVA/BT x -30 films were reduced by 60.3% and 62.0%, respectively, showing good flame retardancy. Importantly, the flexible Ti 3 C 2 T x nanosheets further enhanced the mechanical properties of PVA/BT x composite films. Therefore, this work provides an effective method for the preparation of high thermal conductivity and flame retardant composite materials, which has important potential applications in the microelectronics industry. [Display omitted] • The directional arrangement of BNNS and Ti 3 C 2 T x MXene was achieved by ice-templated assembly. • The flame retardancy of PVA/BT x -30 composite film was greatly improved. • The PVA/BT x -30 composite film exhibited excellent in-plane thermal conductivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The synergistic effect in the flame retardant system improves the fire safety of materials. • The release of toxic fumes limits the application of EVA materials. • The melt produced by piperazine pyrophosphate can effectively inhibit the "popcorn effect" of expandable graphite. Ethylene vinyl acetate copolymer combined with the expandable graphite (EG), pyrophosphate piperazine (PAPP) and melamine polyphosphate (MPP) was adopted to prepare the flame retardant EVA (FREVA) composites by melt blending. The research results showed that the PAPP/EG/MPP mixture with a mass ratio of 2:2:1 presented the optimal flame retardant effect. With the 25 wt% additive amount, EVA composites passed UL-94 V-0 level (1.6 mm), and the limiting oxygen index (LOI) reached 35.2 %. The peak of heat release rate (PHRR), total heat release (THR) and total smoke release decreased by 67.6 %, 60.9 % and 67.4 %, respectively. The Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectra (XPS), scanning electron microscope (SEM), and thermal gravimetric analyzer (TGA) were used to research the synergistic effect flame retardant mechanism of PAPP, EG and MPP in combination with the FTIR spectrometer (TG-FTIR) and the cone calorimeter test (CCT). The polyphosphoric acid non-volatile substances generated by PAPP, attached to the surface of the EG carbon layer, effectively restrained the "popcorn effect", and the char layer presented a compact and stable structure. [ABSTRACT FROM AUTHOR]