• Title/Summary/Keyword: phenylphosphonic acid

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Thermal Stability of Phenylphosphonic Acid Modified Polyurethanes

  • Dong-Eun Kim;Seung-Ho Kang;Sang-Ho Lee
    • Elastomers and Composites
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    • v.58 no.2
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    • pp.70-80
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    • 2023
  • The effect of phenylphosphonic acid (PPOA) on polyurethane (PU) thermal stability was studied through Fourier transform infrared spectroscopy and Thermogravimetric analysis. To synthesize PPOA-modified PUs (PPOA-PUs), polyether-type diols (Mw=62, 106, 190, 419, 605) were chemically modified with PPOA and then reacted with 4,4'-dicyclohexylmethane diisocyanate (H12MDI) and 4,4-diphenylmethane diisocyanate (MDI). During thermal decomposition in air, the PPOA embedded in the PUs formed intumescent phosphocarbonaceous char. Below 400℃, PPOA-H12MDI-PUs were more unstable, as PPOA decomposed at lower temperatures than phenyl groups and aliphatic ethers. Above 550℃, the thermal stability of PUs followed this order: PPOA-MDI-PUs > PPOA-H12MDI-PUs > MDI-PUs > H12MDI-PUs. At 700℃, unmodified PUs had no residue, while the PPOA-MDI-PU residue was 4.4~23.0 wt.% and the PPOA-H12MDI-PU residue was 1.5~17.5 wt.%. The enhanced thermal stability of PPOA-MDI-PUs at high temperatures can be attributed to the synergetic effect of PPOA and phenyl groups on the formation of phosphocarbonaceous char.

Synthesis of Modified Polyesters Containing Triphosphorus for Flame-Retardant Coatings (난연도료용 트리포스포러스 함유 변성폴리에스테르의 합성)

  • Park, Hong-Soo;Yoo, Gyu-Yeol;Kim, Ji-Hyun;Kim, Young-Geun
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.3
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    • pp.287-295
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    • 2007
  • Three phosphorus functional groups were introduced in one structural unit of polymer backbone to enhance the flame retardancy of PU coatings. In the first step, we synthesized tetramethylene bis(orthophosphate) (TBOP) that contained two phosphorus functional groups in one structural unit. In the next step, we synthesized modified polyesters (ATBTP-10C, -20C, -30C) that contained triphosphorus group using TBOP, 1,4-butanediol, trimethylolpropane, adipic acid, and another functional monomer, phenylphosphonic acid (PPA). The amount of PPA in ATBTPs was adjusted from 10 wt% to 30 wt%. The structure and characteristics of ATBTPs were examined using FT-IR, NMR, GPC, and TGA analysis. From the thermo-behavior test of diphosphorus modified polyester (ATBT) and ATBTPs, the afterglow of ATBT, ATBTP-10C, ATBTP-20C, and ATBTP-30C were 24.7, 27.1, 29.0, and 31.7%, respectively. It was found from this result that the afterglow increased with the amount of PPA component.

Physical Properties of Synthetic PU Flame-Retardant Coatings Containing Triphosphorus Modified Polyesters (트리포스포러스 변성폴리에스테르 함유 PU 난연도료의 도막물성)

  • Park, Hong-Soo;Kang, Young-Gu;Kim, Ji-Hyun;Hahm, Hyun-Sik;Keun, Jang-Hyoun
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.2
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    • pp.151-159
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    • 2008
  • The flame-retardant coatings were prepared by blending the synthesized triphosphorus modified polyester in the previous paper and hexamethylene diisocyanate-trimer and curing it at room temperature. The characterization of the films of the prepared coatings was performed. It was confirmed that no deterioration of physical properties of PU coatings was observed with the increasing phenylphosphonic acid (PPA) contents. Flame retardancy was tested by a $45^{\circ}$ Meckel burner method and LOI method. With the $45^{\circ}$ Meckel burner method, CATBTP-20C and CATBTP-30C that contain 20 wt% and 30 wt% of PPA, flame retarding component, respectively, showed the first grade flame retardancy with $2.8{\sim}3.9\;cm$ of char length ; and, with LOI method, they exhibited a good flame retardancy as a range of $30{\sim}32%$ of combustion values.