- Study of thermal properties of intumescent additive : Pentaerythritol phosphate alcohol
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Bicyclic compounds containing phosphorus on their skeleton such as 2,4,6-trioxa-1-phosphabicyclo[2,2,2]octane-4-methanol phosphate (PEPA) having three active ingredients required for intumescence have been synthesized. The structural characterization of PEPA was carried out by FT-IR, 1H and 13C NMR. The thermal behaviour of the material was studied using TGA, TGA-MS and pyrolysis GC-MS. Thermogravimetric analysis reveals that PEPA undergoes several stages of degradation with a char of about 12% at 800 °C. The TGA-MS studies indicate that the material degrades with the liberation of water, formaldehyde, alkene and alcohols as the major degradation products. Pyrolysis GC-MS results reveal that PEPA isomerizes in the acidic medium. PEPA and/or isomers of PEPA react with formaldehyde, one of the degradation products, to form cross-linked structure and cyclic products with the elimination of water molecule. The thermal degradation mechanisms for PEPA are presented and discussed.
- Sarannya, Vijayakumar,Sivasamy, Palanichamy,Mathan, Nagarajan David,Rajkumar, Thangamani,Ponraju, Durairaj,Vijayakumar, Chinnaswamy Thangavel
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- Synthesis of novel caged phosphate esters and their flame retardant effect on poly(vinyl chloride) blends
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Novel caged phosphate esters were synthesized. Flame-retardant mechanism of poly(vinyl chloride) (PVC) blends plasticized with these synthesized caged phosphate esters was investigated with limiting oxygen index (LOI), thermogravi-metric analysis (TGA), scanning electron microscopy (SEM), and cone calorimeter tests. The results showed that caged phosphate esters improved the thermal stabilities of PVC blends: LOI values of PVC blends increased from 24.2% to 35.9%, peak heat release rate decreased from 379.04 to 258.79 kw m-2, and total smoke increased from 1877.9 to 3698.1 m2 m-2; hence, the flame retardancy of PVC blends was improved.
- Jia, Puyou,Zhang, Meng,Hu, Lihong,Feng, Guodong,Zhou, Yonghong
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- Synthesis and characterization of a novel organophosphorus oligomer and its application in improving flame retardancy of epoxy resin
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A novel organophosphorus, poly(4,4-dihydroxy-1-methyl-ethyl diphenol-o-bicyclic pentaerythritol phosphatephosphate) (PCPBO), was synthesized and characterized by FTIR, 1H NMR and 31P NMR. The flame retardancy and thermal stability of epoxy resin with different PCPBO loadings were investigated using the limited oxygen index (LOI), vertical burning test, cone calorimeter test and thermogravimetric analysis. The results showed that the incorporation of PCPBO into epoxy resin (EP) significantly improved its flame retardancy and thermal stability. The reduction of the peak heat release rate, total heat release and the increased char yield at high temperature further confirmed the improvement of the flame retardancy. FT-IR at different temperatures and the scanning electron microscopy of residual char revealed that the addition of PCPBO could induce the formation of an intumescent char layer, which retarded the degradation and combustion process of EP. This journal is the Partner Organisations 2014.
- Tian, Nana,Gong, Jiang,Wen, Xin,Yao, Kun,Tang, Tao
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- Synthesis and characterization of PEDSCD and its application as a flame retardant in epoxy resins
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In this study, a flame retardant agent, called PEDSCD, is synthesized through a polycondensation reaction. PEDSCD is a chemically expanded phosphorus-containing flame retardant, which is introduced in epoxy resin (EP) to improve its flame retardancy. The molecular structure and thermal stability of PEDSCD are characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and thermogravimetric analysis, and EP/PEDSCD composites are investigated in detail. EP/PEDSCD exhibits good stability and flame retardancy. These properties are attributed to the triazine structure introduced into the flame retardant system. The triazine structure starts to decompose at a lower temperature and also reacts with the phosphorus element to form PN-, which increases the viscosity of the melt. This inhibits the generation of smoke and reduces the peak of heat release. PEDSCD shows good thermal stability and low flammability. Further, the weight loss from 500 to 800 °C is only 16 wt%, and the residual mass at 800 °C is 32 wt%. With the addition of PEDSCD, the flame retardant quality of the EP/PEDSCD composites is gradually enhanced, and the carbon residue becomes denser, which isolates the heat transfer and inhibits the volatilization of flue gas. The limited oxygen index (LOI) value of 27% and a vertical burning V-0 rating are achieved when PEDSCD is used in combination with ammonium polyphosphate (APP). The cone calorimeter test shows that the peak heat release rate is reduced by 29% and low gas content is generated, which verifies that the combination of PEDSCD and other phosphorus-containing flame retardants exhibits significantly enhanced flame-retardant properties. PEDSCD exhibits a charring and barrier effect in the condensation phase. Overall, using basic characterization and flame retardancy testing, it is proved that PEDSCD exhibits good flame retardancy when added to EP.
- Zhang, Yi
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p. 34849 - 34859
(2021/12/02)
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- Preparation method and application of novel adamantane-ring-containing phosphorus-silicon flame retardant
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A preparation method and application of a novel phosphorus-silicon flame retardant containing a two-cage phosphate structure are disclosed. Under a condition that N,N-dimethylformamide is adopted as asolvent, anhydrous AlCl3 is adopted as a catalyst and triethylamine is adopted as an acid binder, an intermediate I (double-cage phosphate) reacts with adamantylethyltrichlorosilane to obtain the novel adamantyl-containing phosphorus-silicon flame retardant having white powder appearance. The initial decomposition temperature of the flame retardant is about 362 DEG C, the weight loss at 450 DEG Cis 8%, and the carbon residue yield at 700 DEG C reaches 57%. The flame retardant has good thermal stability, a high carbon residue rate and good flame retardant effect and can be used for halogen-free flame retardation of PC (polycarbonate)/ABS (acrylonitrile-butadiene-styrene copolymer) alloys.
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Paragraph 0024-0026; 0029
(2018/10/19)
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- Synthesis and Biological Activity of 4-[(Substituted Phenoxyacetoxy)methyl]-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-one
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A series of novel 4-[(substituted phenoxyacetoxy)methyl]-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-one 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l, 4m, 4n, 4o were synthesized. Their structures were confirmed by IR,1H NMR, mass spectroscopy, and elemental analyses. The results of preliminary bioassays show that some of the title compounds exhibit moderate to good herbicidal and fungicidal activities. For example, the title compounds 4b, 4c, 4f, 4h, 4i, and 4j possess 90–100% inhibition against the growth of roots of both rape and barnyard grass at 10 mg/L. Moreover, the title compounds 4f, 4g, and 4h possess 75–89% inhibition against Botrytis cinerea at the concentration of 50 mg/L.
- Sheng, Xijun,Zhou, Yuan,Zhang, Shasha,Peng, Hao,He, Hongwu
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p. 165 - 170
(2017/02/03)
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- A bicyclo-cage method for the preparation of phosphoric acid ester flame retardant
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The invention relates to a preparation method of fire retardant of many double ring cage shaped phosphate ester, and the preparation method comprises the following steps: firstly preparing 1-oxygen group phospha-4-trioxabicyclo [2,2,2] octane, carrying out a esterification reaction of 1-oxygen group phospha-4-trioxabicyclo [2,2,2] octane and phosphorous oxychloride further, and obtaining the final products. The intermediate product prepared by the method has a high purity, and the prepared final products have a high purity, high decomposition temperature and high yield. The method has the advantages of simple synthesis, high yield and low cost.
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Paragraph 0020; 0056; 0057; 0058
(2016/10/07)
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- N-P flameresistant material and preparation method thereof and application in textiles
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The invention discloses an N-P flameresistant material and a preparation method thereof and application in textiles. The chemical name of a flame retardant of the material is hexa(1-oxo-phospha-2,6,7-trioxabicyclo[2,2,2]octane-4-methylenedioxy)cyclotriphosphazene (HCPPA); the preparation method of the material comprises the steps of synthesizing hexachlorocyclotriphosphazene (HCPP) by reacting ammonium chloride with phosphorus pentachloride, wherein a catalyst is pyridine and ZnO; then synthesizing 1-oxo-phospha-4-hydroxymethyl-2,6,7-trioxabicyclo[2,2,2]octane (PEPA) by reacting pentaerythritol with phosphorus oxychloride; finally synthesizing the HCPPA by reacting the HCPP with the PEPA. According to the preparation method, NaH is used as a catalyst, so that the synthesis reactions can be performed quickly, the reaction time is greatly shortened, and the product yield is improved. When the N-P flame retardant is used for retarding a flame of a cotton fabric, high limit oxygen index and char yield are achieved, and the wash durability is good.
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Paragraph 0049; 0050; 0051
(2016/10/08)
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- Synthesis of an intrinsically flame retardant bio-based benzoxazine resin
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An intrinsically flame retardant bio-based benzoxazine (diphenolic acid pentaerythritol caged phosphate benzoxazine, DPA-PEPA-Boz) monomer was synthesized from bio-based diphenolic acid (DPA) using a four-step process. The monomer of DPA-PEPA-Boz was characterized by FT-IR, 1H NMR and 13C NMR. The curing behavior of DPA-PEPA-boz was studied and compared with those of DPA based benzoxazine (DPA-Boz) and DPA ester derivative (MDP) based benzoxazine (MDP-Boz) without PEPA by means of non-isothermal differential scanning calorimetry. The results indicated that DPA-PEPA-Boz system showed a two-stage curing, assigned to the exothermic opening reactions of oxazine rings and P-O-C ring in PEPA respectively, while the DPA-Boz and MDP-Boz showed a one-stage curing. In addition, the effect of the introduction of PEPA on thermal and inflammable properties of the resin was evaluated. The residual char of the cured DPA-PEPA-Boz (P-DPA-PEPA-Boz) after 400 °C was much higher than those of cured DPA-Boz (P-DPA-Boz) and cured MDP-Boz (P-MDP-Boz) under nitrogen and air atmospheres. Meanwhile, total heat release (THR), peak heat release rate (PHRR) and heat release capacity (HRC) of P-DPA-PEPA-Boz were about half of those of P-DPA-Boz and P-MDP-Boz. P-DPA-PEPA-Boz had a limiting oxygen index (LOI) of 33.5% and achieved V0 rating in UL94 test. P-DPA-PEPA-Boz behaved as a very good intrinsic thermal and flame retardant bio-based benoxazine resin.
- Yan, Hongqiang,Sun, Chuang,Fang, Zhengping,Liu, Xiaoqing,Zhu, Jin,Wang, Hao
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p. 418 - 427
(2016/06/09)
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- Synthesis of novel bicycli caged phosphate derivatives
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A series of bicycli caged phosphates were synthesized, and biological activity test showed that the title compounds exhibited moderate herbicidal activity. Copyright Taylor & Francis Group, LLC.
- Mo, Wen-Yan,He, Hong-Wu
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p. 699 - 700
(2009/04/11)
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- Method for preparing pentaerythritol phosphate alcohol by mechanochemical synthesis
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Mechanochemical synthesis of pentaerythritol phosphate alcohol is disclosed. The synthesis is carried out by ball milling a mixture containing P2O5, pentaerythritol, an alkyl benzene having one or two C1-C5 alkyl groups, and a metal halide catalyst, in a ball mill as a reactor and at a temperature of 70-150° C.
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