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. 2022 Jan 21;14(3):420.
doi: 10.3390/polym14030420.

Acoustic Performance and Flame Retardancy of Ammonium Polyphosphate/Diethyl Ethylphosphonate Rigid Polyurethane Foams

Huiping Zhang  1 , Xiongxian Lyu  1 , Zijun Huang  1 , Ying Yan  1
Affiliations

Acoustic Performance and Flame Retardancy of Ammonium Polyphosphate/Diethyl Ethylphosphonate Rigid Polyurethane Foams

Huiping Zhang et al. Polymers (Basel). .

Abstract

Flame-retardant water-blown rigid polyurethane foams (RPUFs) modified by ammonium polyphosphate (APP) and diethyl ethylphosphonate (DEEP) were synthesized by a one-pot free-rising method. We performed scanning electron microscopy (SEM), compression strength tests, acoustic absorption measurements and thermogravimetric analysis, as well as limited oxygen index, vertical burning and cone calorimeter tests to investigate the mechanical properties, acoustic performance and flame retardancy of the foams. SEM confirmed that the open-cell structures of the foams were successfully constructed with the introduction of a cell-opening agent. Upon using 20 php APP, the average acoustic absorption coefficient of the foam reached 0.535 in an acoustic frequency range of 1500-5000 Hz. The results of thermogravimetric analysis demonstrated that the incorporation of APP and DEEP can effectively restrain mass loss of RPUFs during pyrolysis. In particular, the compressive strength of a foam composite containing 5 php APP and 15 php DEEP increased to 188.77 kPa and the LOI value reached 24.9%. In a vertical burning test and a cone calorimeter test, the joint use of APP and DEEP endowed RPUFs with a V-0 rating and they attained a THR value of 23.43 MJ/m2. Moreover, the addition of APP improved the acoustic absorption performance of the foam, verified by acoustic absorption measurements. Considering potential applications, the formulation containing 15 php APP and 5 php DEEP could be used in the preparation of a new flame-retardant acoustic absorption rigid polyurethane foam.

Keywords: acoustic absorption; flame retardant; open-cell structure; rigid polyurethane foam.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
FTIR spectra of RPUF, RPUF/APP15/DEEP5, RPUF/APP5/DEEP15, APP and DEEP.
Figure 2
Figure 2
SEM images and pore size distribution of prepared foams. (a1,a2) RPUF, (b1,b2) O-RPUF, (c1,c2) RPUF/APP20, (d1,d2) RPUF/DEEP20, (e1,e2) RPUF/APP15/DEEP5, (f1,f2) RPUF/APP5/DEEP15.
Figure 3
Figure 3
Relationship between apparent density and compression strength of various RPUFs.
Figure 4
Figure 4
Acoustic absorption coefficient–frequency curves ranging from 125 to 5000 Hz of various RPUFs.
Figure 5
Figure 5
Thermogravimetric (TGA) and differential thermogravimetric (DTG) curves of different samples.
Figure 6
Figure 6
SEM images of char residue after vertical burning tests of RPUF loading different kinds and contents of flame retardants. (a,b) Surface of burnt O-RPUF; (c,d) cross section and surface of burnt RPUF/APP20; (e,f) cross section and surface of burnt RPUF/DEEP20; (g,h) cross section and surface of burnt RPUF/APP15/DEEP15; (i,j) cross section and surface of burnt RPUF/APP5/DEEP15. Small particles are framed using circles and parts of the corrugated surface are framed using rectangles.
Figure 7
Figure 7
HRR curves and THR curves of O-RPUF, RPUF/APP, RPUF/DEEP and RPUF/APP/DEEP.
See this image and copyright information in PMC

References

    1. Engels H.-W., Pirkl H.-G., Albers R., Albach R.W., Krause J., Hoffmann A., Casselmann H., Dormish J. Polyurethanes: Versatile Materials and Sustainable Problem Solvers for Today’s Challenges. Angew. Chem. Int. Ed. 2013;52:9422–9441. doi: 10.1002/anie.201302766. - DOI - PubMed
    1. Sagartzazu X., Hervella-Nieto L., Pagalday J.M. Review in Sound Absorbing Materials. Arch. Comput. Methods Eng. 2008;15:311–342. doi: 10.1007/s11831-008-9022-1. - DOI
    1. Hoang M.T., Bonnet G., Tuan Luu H., Perrot C. Linear Elastic Properties Derivation from Microstructures Representative of Transport Parameters. J. Acoust. Soc. Am. 2014;135:3172–3185. doi: 10.1121/1.4872296. - DOI - PubMed
    1. Johnson D.L., Koplik J., Dashen R. Theory of Dynamic Permeability and Tortuosity in Fluid-Saturated Porous Media. J. Fluid Mech. 1987;176:379. doi: 10.1017/S0022112087000727. - DOI
    1. Champoux Y., Allard J. Dynamic Tortuosity and Bulk Modulus in Air-saturated Porous Media. J. Appl. Phys. 1991;70:1975–1979. doi: 10.1063/1.349482. - DOI

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