Synthesis and Characterization of Halogen-Free Flame Retardant Two-Component Waterborne Polyurethane by Different Modification

Aminophosphonated polyols with flame retardant properties are synthesized by ring opening polymerization using diethyl-N,N-bis(2-hydroxyethyl) aminomethyl phosphonate (Fyrol-6) as initiator. The influence of the catalyst type and its concentration on the polymerization rate are studied. The catalyst system formed by potassium methoxide (MeOK) in DMSO as a solvent presents the highest polymerization rate and allows reducing the polydispersity. The thermal resistance of the synthesized polyols is confirmed by the char residues formation. Finally, PU foams are synthesized containing up to a 50 pph of PFyCs[1:1], preserving good cellular structure up to a 25 pph content and improving the fire resistance by increasing the char residue from 7.79 to 22.13 wt % and decreasing the PHRR and the smoke production according to TGA and cone calorimeter tests, respectively.

Section: Introductionmentioning

confidence: 99%

Synthesis of aminophosphonate polyols and polyurethane foams with improved fire retardant properties

Borreguero

Velencoso

Rodrı́guez

et al. 2019

“…It could be seen from Figure 12 that there were no obvious characteristic peaks except that 1,530 cm −1 (─NH─) and 1,688 cm −1 (P─OH) on the curve of 200 C, indicating that there was no large amount of decomposition of the substance, which was consisted with TG test (as shown in Table 6, T 5% was higher than 230 C). [36,37] There was obvious characteristic peak of CO 2 at 2,356 cm −1 and ─NCO at 2,316 cm −1 on the curves of 250 C and 300 C, respectively. That was possible due to the production of CO 2 and ─NCO groups at the decomposition of urethane groups (─NHCOO─) in the polyurethane chains.…”

Section: Thermal Gravimetric Analysismentioning

confidence: 91%

Preparation and characterization of the halogen‐free, smoke suppression, organic–inorganic hybrid flame‐retardant expandable polystyrene materials

Zhang

2020

Expandable polystyrene (EPS) is a plastic widely used in the field of construction, but it is flammable. This work provided a novel strategy for flame‐retardant modification of EPS. A kind of polyester polyol (JZP) with the high content of phosphorus and nitrogen was synthesized. Then, intrinsic flame‐retardant polyurethane (PFWPU) with the high content of phosphorus and nitrogen was synthesized by JZP acted as soft segment chain extender. Finally, a high‐efficiency flame‐retardant expandable polystyrene thermal insulation material (AF‐EPS) was prepared by the organic–inorganic hybrid flame‐retardant synergistic action of PFWPU and ammonium polyphosphate. The effects of different contents of inorganic flame retardants on flame retardancy of materials were studied by limiting oxygen index (LOI), cone calorimetry, thermogravimetric analysis/infrared spectrometry , scanning electron microscopy, and so on. The test results showed that the carbon residue rate of the modified material increased from 0 to 28.5%, the LOI increased from 17 to 35.8%, and the vertical combustion test reached the highest grade V‐0. In addition, the total smoke production of AF‐EPS samples decreased from 2.33 m2 to 0.57 m2, the time to ignition was increased to 41 s, and the peak heat release rate and the total heat release were decreased by 90.2 and 62.7%, respectively.

“…As far as we know, nitrogen‐phosphorus flame retardants (IFRs) are regard to be the desired candidates due to their superior advantages including lower pollution and high flame‐retardant efficiency. Unfortunately, low‐molecular‐weight IFRs generally lack in molecular weights and migrate readily to the polymer surface, although the conventional process of introducing reactive small molecule FR into WPU is simple . For this reason, enormous studies focused on new kind of intumescent flame retardant have been carried out.…”

Section: Introductionmentioning

confidence: 99%

Highly effective flame‐retarded polyester diol with synergistic effects for waterborne polyurethane application

Wang

et al. 2019

In this article, a novel bi-reactive flame retardant (FRD) was successfully synthesized for waterborne polyurethane (WPU). The chemical structures of FRD were characterized by Fourier-transform infrared spectra and 1 H and 31 P nuclear magnetic resonance. Then, the FRD was incorporated into polyurethane backbone to prepare a series of flame-retarded WPU (FRWPU). The flammability characteristics of FRWPU were measured by limited oxygen index (LOI), UL-94, and cone calorimeter (CCT) tests. The FRPWU-7 had a high LOI value of 30.5% with UL94 V-0 rating. Moreover, the CCT values indicated that FRD induced the gaseous phase quenching effect of phosphoruscontaining free radicals derived from the decomposed phosphaphenanthrene group on the gas-phase flame retardancy. Scanning electron micrographs and Raman spectra exhibited that FRD promoted the charring formation of phosphorus-rich char layer with graphitized surface and honeycomb-like intumescent structure in WPU matrix during burning. This study provides a new way to design a novel reactive P-P flame retardant consisted of the phosphaphenanthrene group and intumescent flame retardant for WPU application.