Enhancing the Fire Safety and Smoke Safety of Bio–Based Rigid Polyurethane Foam via Inserting a Reactive Flame Retardant Containing P@N and Blending Silica Aerogel Powder

Abstract

Rigid polyurethane foams (RPUFs) are widely used in many fields, but they are easy to burn and produce a lot of smoke, which seriously endangers the safety of people’s lives and property. In this study, tetraethyl(1,5–bis(bis(2–hydroxypropyl)amino)pentane–1,5–diyl)bis(phosphonate) (TBPBP), as a phosphorus–nitrogen–containing reactive–type flame retardant, was successfully synthesized and employed to enhance the flame retardancy of RPUFs, and silica aerogel (SA) powder was utilized to reduce harmful fumes. Castor oil–based rigid polyurethane foam containing SA powder and TBPBP was named RPUF–T45@SA20. Compared with neat RPUF, the obtained RPUF–T45@SA20 greatly improved with the compressive strength properties and the LOI value increased by 93.64% and 44.27%, respectively, and reached the V–0 rank of UL–94 testing. The total heat release (THR) and total smoke production (TSP) of RPUF–T45@SA20 were, respectively, reduced by 44.66% and 51.89% compared to those of the neat RPUF. A possible flame–retardant mechanism of RPUF–T45@SA20 was also proposed. This study suggested that RPUF incorporated with TBPBP and SA powder is a prosperous potential composite for fire and smoke safety as a building insulation material.

Cost-Effective Fabrication of Modified Palygorskite-Reinforced Rigid Polyurethane Foam Nanocomposites

“…Based on the TG and DTG curves, all the nanocomposites exhibit a similar behavior during heating. The thermal decomposition can be divided into three stages: the first stage is the evaporation of water and the volatilization of small molecules such as a foaming agent in the range of 80-200 °C [36,37]; the second stage is the degradation of the hard segment of the polyurethane molecular chain at To evaluate the thermal stability of the Pal/RPUFNs, TG and DTG curves are presented in Figures 8a and 8b, respectively. Based on the TG and DTG curves, all the nanocomposites exhibit a similar behavior during heating.…”

“…Based on the TG and DTG curves, all the nanocomposites exhibit a similar behavior during heating. The thermal decomposition can be divided into three stages: the first stage is the evaporation of water and the volatilization of small molecules such as a foaming agent in the range of 80-200 • C [36,37]; the second stage is the degradation of the hard segment of the polyurethane molecular chain at 200-400 • C, with the weight loss up to 60-70% in this stage [36,38]; and the third stage is from 400 • C to 800 • C, corresponding to the oxidative decomposition of soft isocyanates and aromatic compounds (mainly aromatic rings) in the polyurethane molecular chain. Specifically, the C-H bonds of aromatic rings are broken to form radical fragments containing aromatic ring structures, and then further dehydrogenation and condensation reactions occur between the aromatic rings to eventually form solid carbon-based residues.…”

Surface Flame-Retardant Systems of Rigid Polyurethane Foams: An Overview

“…The aerogel consists of a microporous solid and is made from inorganic compounds or organic polymers [ 32 ]. Among them, silica aerogels, an ideal candidate for both thermal insulation and flame-retardant applications, have been extensively studied [ 32 , 46 , 47 , 48 , 49 , 50 ]. The unique nanoporous network skeleton of the aerogel confers special properties, such as low density, low thermal conductivity, and small average pore diameter.…”

Recent Developments in Biobased Foams and Foam Composites for Construction Applications

“…Various studies have focused on the replacement of the polyols obtained conventionally from fossilbased sources to renewable and green polyols. A significant challenge is their high flammability that deters their commercial use [23,[33][34][35][36][37][38][39][40].…”