Novel MoS₂–DOPO Hybrid for Effective Enhancements on Flame Retardancy and Smoke Suppression of Flexible Polyurethane Foams

Abstract

A novel MoS2–DOPO hybrid has been successfully synthesized through the grafting of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) on the surface of MoS2 nanosheets using allyl mercaptan as an intermediate. MoS2–DOPO was used as a flame retardant additive to prepare flame-retardant flexible polyurethane foam (FPUF). The influence of MoS2–DOPO on the mechanical, thermal stability, and flame retardancy properties of FPUF composites were systematically investigated. The incorporation of MoS2–DOPO could not deteriorate greatly the tensile strength and 50% compression set of FPUF composites, but effectively improves the char residue. The cone calorimeter and smoke density tests results revealed that the peak heat release rate, total heat release, and the maximum smoke density of the MoS2–DOPO/FPUF composite were reduced by 41.3, 27.7, and 40.5%, respectively, compared with those of pure FPUF. Furthermore, the char residue after cone calorimeter tests and pyrolysis gaseous products of the MoS2–DOPO/FPUF composite were analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and thermogravimetric analysis/infrared spectrometry. The results suggested that the MoS2–DOPO hybrid played a synergistic flame retardant effect of gas and condensed bi-phase action. In addition, a possible flame retardancy and smoke suppression mechanism of the MoS2–DOPO/FPUF composite were proposed. This study provides a facile and promising strategy for the fabrication of polymer materials with excellent flame retardancy and smoke suppression properties.

Chemically modified carbon nanostructures and 2D nanomaterials for fabrics performing under operational tension and extreme environmental conditions

“…The modified MoS 2 has shown great flame resistance and smoke suppression in polyurethane foam but is yet to be tested on yarn or fabric. 70…”

Solubility Determination and Data Correlation of a New Flame Retardant 3,9-Bis(phenyl(phenylamino)methyl)-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane 3,9-dioxide in 12 Pure Solvents from 283.15 to 343.15 K

“…reported that the application of natural and synthetic polymer materials is one of the causes of frequent fires. − Polymers with improved flame retardancy have received great attention in the industry. At present, flame retardants containing elements such as phosphorus, nitrogen, and halogen are being widely studied and applied. − However, flame retardant polymeric materials containing halogens produce a large amount of toxic smoke during combustion. This seriously harms the environment and people’s health.…”

Improvement of Flame Retardancy of Polyurethane Foam Using DOPO-Immobilized Silica Aerogel

“…Among them, phosphorus-containing flame retardants, especially 9,10dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives, have attracted much attention (Huo et al, 2020;Huo et al, 2021). 9,10-Dihydro-9-oxa-10-phenanthrene-10oxide (DOPO) and its derivatives were used to improve their use as flame retardants, as these have higher thermal stability, excellent flame retardancy, and low toxicity (Ma et al, 2020;Zhi et al, 2020).…”