Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing Cyclotriphosphazene

To study the properties of cyclotriphosphazene (CTP)-containing phthalonitriles, a branched phthalonitrile containing CTP (CTP–PN) with self-catalytic behavior was designed and synthesized. The structure of CTP–PN was characterized by FT–IR (Fourier transform infrared spectroscopy), MS (mass spectro...

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Main Authors: Dengxun Ren, Zexu Fan, Jiaqu Zhang, Yi Xu, Xianzhong Tang, Mingzhen Xu
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Molecules
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Online Access:https://www.mdpi.com/1420-3049/29/23/5668
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author Dengxun Ren
Zexu Fan
Jiaqu Zhang
Yi Xu
Xianzhong Tang
Mingzhen Xu
author_facet Dengxun Ren
Zexu Fan
Jiaqu Zhang
Yi Xu
Xianzhong Tang
Mingzhen Xu
author_sort Dengxun Ren
collection DOAJ
description To study the properties of cyclotriphosphazene (CTP)-containing phthalonitriles, a branched phthalonitrile containing CTP (CTP–PN) with self-catalytic behavior was designed and synthesized. The structure of CTP–PN was characterized by FT–IR (Fourier transform infrared spectroscopy), MS (mass spectroscopy), <sup>1</sup>H–NMR (proton nuclear magnetic resonance spectroscopy), and <sup>13</sup>C–NMR (carbon nuclear magnetic resonance spectroscopy). Then, the curing reaction of CTP–PN was studied using DSC (differential scanning calorimetry) and DRA (dynamic rheological analysis). The results show that the curing reaction of CTP–PN is initiated at 200 °C. Additionally, the change in the viscosity of CTP–PN as a function of the temperature was investigated. After curing at different temperatures, the generated structures were characterized by FT–IR. The fracture morphology and thermomechanical properties of cured CTP–PN were scanned and studied using SEM (scanning electron microscopy) and TMA (thermomechanical analysis), respectively. The results demonstrate that CTP–PN exhibits a smooth fracture surface and possesses a relatively low CTE (coefficient of linear thermal expansion) of approximately 25 ppm/°C at 285 °C. A <i>T</i><sub>d5%</sub> (temperature at which 5% weight loss occurs) of as high as 405 °C can be obtained for cured CTP–PN, and its char yield at 800 °C exceeds 70% in N<sub>2</sub>. FT–IR and XPS (X-ray photoelectron spectroscopy) were used to study the thermal decomposition of cured CTP–PN, indicating that it remains stable below 350 °C. With an increasing temperature, there is decomposition first of CTP and P–NH–Ph and C–O–C bonds (>350 °C) and then nitrogen-containing aromatic heterocycles (>500 °C), ultimately resulting in the formation of P-containing residual char.
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series Molecules
spelling doaj-art-b74e9dac0acf439581e37fe4e9f36a782024-12-13T16:28:39ZengMDPI AGMolecules1420-30492024-11-012923566810.3390/molecules29235668Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing CyclotriphosphazeneDengxun Ren0Zexu Fan1Jiaqu Zhang2Yi Xu3Xianzhong Tang4Mingzhen Xu5School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, ChinaSchool of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, ChinaSchool of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, ChinaSchool of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, ChinaSchool of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, ChinaSchool of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, ChinaTo study the properties of cyclotriphosphazene (CTP)-containing phthalonitriles, a branched phthalonitrile containing CTP (CTP–PN) with self-catalytic behavior was designed and synthesized. The structure of CTP–PN was characterized by FT–IR (Fourier transform infrared spectroscopy), MS (mass spectroscopy), <sup>1</sup>H–NMR (proton nuclear magnetic resonance spectroscopy), and <sup>13</sup>C–NMR (carbon nuclear magnetic resonance spectroscopy). Then, the curing reaction of CTP–PN was studied using DSC (differential scanning calorimetry) and DRA (dynamic rheological analysis). The results show that the curing reaction of CTP–PN is initiated at 200 °C. Additionally, the change in the viscosity of CTP–PN as a function of the temperature was investigated. After curing at different temperatures, the generated structures were characterized by FT–IR. The fracture morphology and thermomechanical properties of cured CTP–PN were scanned and studied using SEM (scanning electron microscopy) and TMA (thermomechanical analysis), respectively. The results demonstrate that CTP–PN exhibits a smooth fracture surface and possesses a relatively low CTE (coefficient of linear thermal expansion) of approximately 25 ppm/°C at 285 °C. A <i>T</i><sub>d5%</sub> (temperature at which 5% weight loss occurs) of as high as 405 °C can be obtained for cured CTP–PN, and its char yield at 800 °C exceeds 70% in N<sub>2</sub>. FT–IR and XPS (X-ray photoelectron spectroscopy) were used to study the thermal decomposition of cured CTP–PN, indicating that it remains stable below 350 °C. With an increasing temperature, there is decomposition first of CTP and P–NH–Ph and C–O–C bonds (>350 °C) and then nitrogen-containing aromatic heterocycles (>500 °C), ultimately resulting in the formation of P-containing residual char.https://www.mdpi.com/1420-3049/29/23/5668cyclotriphosphazenebranched phthalonitrilecuring reactionthermomechanical propertiesthermal decomposition analysis
spellingShingle Dengxun Ren
Zexu Fan
Jiaqu Zhang
Yi Xu
Xianzhong Tang
Mingzhen Xu
Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing Cyclotriphosphazene
Molecules
cyclotriphosphazene
branched phthalonitrile
curing reaction
thermomechanical properties
thermal decomposition analysis
title Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing Cyclotriphosphazene
title_full Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing Cyclotriphosphazene
title_fullStr Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing Cyclotriphosphazene
title_full_unstemmed Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing Cyclotriphosphazene
title_short Synthesis and Investigation of the Properties of a Branched Phthalonitrile Containing Cyclotriphosphazene
title_sort synthesis and investigation of the properties of a branched phthalonitrile containing cyclotriphosphazene
topic cyclotriphosphazene
branched phthalonitrile
curing reaction
thermomechanical properties
thermal decomposition analysis
url https://www.mdpi.com/1420-3049/29/23/5668
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AT yixu synthesisandinvestigationofthepropertiesofabranchedphthalonitrilecontainingcyclotriphosphazene
AT xianzhongtang synthesisandinvestigationofthepropertiesofabranchedphthalonitrilecontainingcyclotriphosphazene
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