Flame retardancy and thermal properties of rigid polyurethane foam conjugated with a phosphorus–nitrogen halogen-free intumescent flame retardant

2020 ◽  
Vol 38 (3) ◽  
pp. 235-252
Author(s):  
Zhaojun Lin ◽  
Qianqiong Zhao ◽  
Ruilan Fan ◽  
Xiaoxue Yuan ◽  
Fuli Tian
Keyword(s):  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Flame Retardant ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Carbon Layer ◽  
Limited Oxygen Index ◽  
Halogen Free ◽  
Limited Oxygen

In this work, a halogen-free intumescent combining phosphorus and nitrogen, flame-retardant 2-((2-hydroxyphenyl)(phenylamino)methyl5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide (HAPO) was successfully synthesized. It had been synthesized by reaction of 5,5-dimethyl-1,3, 2-dioxphosphinane 2-oxide with Schiff base. Its chemical structure was characterized in detail by Fourier transform infrared spectroscopy, 1H NMR, and 31P NMR spectrum. The flame-retardant polyurethanes were prepared with different loadings of HAPO. The thermal properties, flame retardancy and combustion behavior of the pure polyurethane foam thermosets were investigated by a series of measurements involving thermogravimetric analysis, limited oxygen index measurement, UL-94 vertical burning test, and cone calorimeter test. The results of the aforementioned tests indicated that HAPO can significantly improve the flame retardancy as well as smoke inhibition performance of polyurethane foam. Compared with the PU-Neat, the limited oxygen index of flame-retardant polyurethanes (15%) thermoset was increased from 19.5% to 23.8% and its UL-94 reached V-0 rating. In addition, the cone test results showed that the heat release rate, total heat release, rate of smoke release, and total smoke production of flame-retardant polyurethanes (10%) were decreased obvious sly. The apparent morphology of carbon residue was characterized by scanning electron microscopy, and results revealed that the modified polyurethane foam can form dense carbon layer after combustion. Thermogravimetric analysis results also indicated that the char amount of flame-retardant polyurethanes was obviously increased compared with PU-Neat. Based on the above analysis, we can draw the conclusions which in the condensed phase, phosphorus-based acids from the degradation of HAPO, this could promote the formation of continuous and dense phosphorus-rich carbon layer. In the gas phase, the flame-retardant mechanism was ascribed to the quenching effect of phosphorus-based radicals and diluting effect by non-flammable gases.

Synthesis of a Flame Retardant for Epoxy Resins: Thermal Stability, Flame Retardancy, and Flame-Retardant Modes

2021 ◽  
Vol 36 (2) ◽  
pp. 172-184
Author(s):  
Y. Zhang ◽  
J. Liu ◽  
S. Li
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Heat Release ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Limited Oxygen Index ◽  
Index Value ◽  
Limited Oxygen

Abstract A polyphosphonate (PDPA) flame retardant that contains phenyl phosphonic dichloride and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide groups, has been synthesized. The flame retardant was introduced into epoxy resins (EP) and cured by 4,4’-diamino diphenylmethane. The vertical burning, limited-oxygen index and cone calorimeter tests reveal that the PDPA can enhance the flame-retardant properties of the EP significantly. With only a 4 wt% PDPA loading, the EP composites achieved a limited-oxygen index value of 33.4% and a V-0 rating in the vertical burning test, and the peak heat release rate and total heat release were decreased by 40.9% and 24.6%, respectively. The thermal properties and gas pyrolysis products of the EP composites were evaluated by thermogravimetric analysis and thermogravimetric analysis-Fourier transform infrared spectroscopy, and the morphology and structure of residual char were characterized by scanning electron microscopy, Flourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. To explain the combined effects of the condensed and gas phases, modes of the flame-retardant action are proposed.

Flame Retardancy of Lanthanum Phosphinate in Combination with Intumescen Flame-Retardant in Polypropylene

2012 ◽  
Vol 490-495 ◽  
pp. 3366-3369 ◽  
Author(s):  
Cong Liu
Keyword(s):  
Thermogravimetric Analysis ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Intumescent Flame Retardant ◽  
Limiting Oxygen Index ◽  
Ul 94 ◽  
Halogen Free

The flame-retardant of Lanthanum phenylphosphinate(LaPi) was prepared and its combination with intumescent flame retardant (IFR) in polypropylene (PP) was analysed using thermogravimetric analysis (TGA), limiting oxygen index (LOI) and the UL-94 test. Compared with using IFR alone, using the combination of LaPi and IFR gained the better classification in the UL 94 test thanks to the combination of the different mechanisms. When 20 wt% loading of flame retardant of LaPi and IFR, a halogen-free V-0 PP material was achieved with a LOI of 31%.

scholarly journals Polycarbonate/Sulfonamide Composites with Ultralow Contents of Halogen-Free Flame Retardant and Desirable Compatibility

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3656
Author(s):  
Hangfeng Yang ◽  
Hangbo Yue ◽  
Xi Zhao ◽  
Minzimo Song ◽  
Jianwei Guo ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Smoke Emission ◽  
Limiting Oxygen Index ◽  
Ul 94 ◽  
Flame Retardant Properties ◽  
Halogen Free ◽  
Sem Morphology ◽  
Limited Oxygen

A novel halogen-free flame retardant containing sulfonamide, 1,3,5,7-tetrakis (phenyl-4-sulfonamide) adamantane (FRSN) was synthesized and used for improving the flame retardancy of largely used polycarbonate (PC). The flame-retardant properties of the composites with incorporation of varied amounts of FRSN were analyzed by techniques including limited oxygen index, UL 94 vertical burning, and cone calorimeter tests. The new FR system with sulfur and nitrogen elements showed effective improvements in PC’s flame retardancy: the LOI value of the modified PC increased significantly, smoke emission suppressed, and UL 94 V-0 achieved. Typically, the composite with only 0.08 wt% of FRSN added (an ultralow content) can increase the limiting oxygen index (LOI) value to 33.7% and classified as UL 94 V-0 rating. Furthermore, the mechanical properties and SEM morphology indicated that the FRSN has very good compatibility with PC matrix, which, in turn, is beneficial to the property enhancement. Finally, the analysis of sample residues after burning tests showed that a high portion of char was formed, contributing to the PC burning protection. This synthesized flame retardant provides a new way of improving PC’s flame retardancy and its mechanical property.

scholarly journals The Preparation, Thermal Properties, and Fire Property of a Phosphorus-Containing Flame-Retardant Styrene Copolymer

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 127 ◽  
Author(s):  
Yu Sun ◽  
Yazhen Wang ◽  
Li Liu ◽  
Tianyuan Xiao
Keyword(s):  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Chemical Structures ◽  
1H Nuclear Magnetic Resonance ◽  
Phosphorus Containing ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) acrylate, (6-oxidodibenzo [c,e][1,2] oxaphosphinin-6-yl) methyl acrylate (DOPOAA), has been prepared. Copolymers of styrene (St) and DOPOAA were prepared by emulsion polymerization. The chemical structures of copolymers containing levels of DOPOAA were verified using Fourier transform infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H-NMR) spectroscopy. The thermal properties and flame-retardant behaviors of DOPO-containing monomers and copolymers were observed using thermogravimetric analysis and micro calorimetry tests. From thermogravimetric analysis (TGA), it was found out that the T5% for decomposition of the copolymer was lower than that of polystyrene (PS), but the residue at 700 °C was higher than that of PS. The results from micro calorimetry (MCC) tests indicated that the rate for the heat release of the copolymer combustion was lower than that for PS. The limiting oxygen index (LOI) for combustion of the copolymer rose with increasing levels of DOPOAA. These data indicate that copolymerization of the phosphorus-containing flame-retardant monomer, DOPOAA, into a PS segment can effectively improve the thermal stability and flame retardancy of the copolymer.

scholarly journals Effects of collagen fiber addition on the combustion and thermal stability of natural rubber

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Weixing Xu ◽  
Xintao Wu ◽  
Qilin Wen ◽  
Shuangyang Li ◽  
Yongjiao Song ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Flame Retardant ◽  
Nitrogen Content ◽  
Flame Retardancy ◽  
Collagen Fiber ◽  
Oxygen Index ◽  
Air Pockets ◽  
Thermal Stability Of ◽  
Limited Oxygen ◽  
Properties Of Composites

Abstract Collagen fiber (CF) and silane coupling agent-modified collagen fiber (MCF) were used as flame retardant filler for natural rubber (NR) modification. The combustion phenomena and properties of composites blended with different dosages of CF or MCF were compared to elucidate the flame retardant mechanism of the composites. The flame retardancy of NR can be enhanced effectively by increasing nitrogen content (the nitrogen content of CF is about 18%), creating air pockets, and structuring the flame retardant network in the composites. MCF failed to structure a flame retardant network in the composite, indicating that its modification effects of MCF are weaker than those of CF. When CF dosage was 30 wt%, the composite can achieve the best flame retardancy, with limited oxygen index of 29.4% and without smoke and dripping during burning. This study demonstrated a new method for the flame retardant modification of NR. Graphical abstract

Synergistic Effect between Montmorillonite Intercalated by Melamine and Intumescent Flame Retardant (IFR) on Polypropylene

2011 ◽  
Vol 295-297 ◽  
pp. 315-318
Author(s):  
Hong Fang Zhu ◽  
Juan Li ◽  
Liang Xu ◽  
Kang Tao ◽  
Li Xin Xue ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Flame Retardant ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Intumescent Flame Retardant ◽  
Limited Oxygen Index ◽  
Cation Exchange Reaction ◽  
Melamine Salt ◽  
Better Than ◽  
Limited Oxygen

This Montmorillonite modified by melamine (MA-MMT) was prepared via cation exchange reaction by using melamine salt as intercalation reagent. MA-MMT and Na-MMT was combined with intumescent flame retardant (IFR) to be adopted into polypropylene (PP), respectively. The synergistic effect between MA-MMT and IFR and the influence of melamine in MMT layers on fire-resistant performance was evaluated. Results of limited oxygen index (LOI) tests and UL-94 tests indicate that melamine salts in MMT layers behaved better than Na-MMT in PP/IFR system. According to the results of cone calorimeter tests and scanning electron microscope (SEM), it concludes that melamine salts act as gas agent to provide migration impetus and expanded power, which caused a well-structured and strong char that had better ability to endure heat erosion. A good synergistic effect between MA-MMT and IFR is constructed.

Flame-Retardant Properties of Polyester Fabrics Reinforced Phenolic Resin Modified with Silazanes Composites

2015 ◽  
Vol 1120-1121 ◽  
pp. 519-522
Author(s):  
Xiao Wen Ren ◽  
Ya Ping Zhu ◽  
Fan Wang ◽  
Hui Min Qi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Flame Retardant ◽  
Phenolic Resin ◽  
Oxygen Index ◽  
Phenolic Resins ◽  
Polyester Fabrics ◽  
Limited Oxygen Index ◽  
Flame Retardant Properties ◽  
Limited Oxygen

Phenolic resin modified with methylvinylcyclosilazanes (MVSZ) were prepared and their flame-retardant properties were investigated, and results exhibited that the Limited Oxygen Index (LOI) values increased with the content increasing of MVSZ, and the LOI reach to 40.8, when the content of MVSZ was 26.0%. The flame-retardant and mechanical properties of polyester fabrics reinforced phenolic resin modified with silazanes (PFMS) composites were measured, the results indicated that the LOI and flexural strength were enhanced compared with those of phenolic resins composites.

Study on the Synthesis and Characterization of a Novel Phosphorus-Nitrogen Containing Intumescent Flame Retardant

2011 ◽  
Vol 399-401 ◽  
pp. 1376-1380
Author(s):  
Li Hua You ◽  
Yin Yin Hui ◽  
Xiang Ning Shi ◽  
Zhi Han Peng
Keyword(s):  
Molecular Structure ◽  
Thermal Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Phosphinic Acid ◽  
Intumescent Flame Retardant ◽  
Synthesis And Characterization ◽  
Limiting Oxygen Index

In this study, a novel phosphorus-nitrogen containing intumescent flame retardant (P-N IFR) poly(melamine 2-carboxyethyl(phenyl) phosphate)(PMCEP) was prepared via the reaction of 2-carboxyethyl (phenyl) phosphinic acid (CEPPA) and melamine (MEL) in two-steps. Meanwhile, the molecular structure of the chemical compound was determined by FTIR,1H-NMR and elemental analysis; and the thermal properties was investigated by means of TGA. Combustion studies revealed high limiting oxygen index (LOI) indicative of better flame-retardancy properties for PBT resin.

The effects of N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol on the flame retardancy and physical–mechanical properties of rigid polyurethane foams

2018 ◽  
Vol 36 (6) ◽  
pp. 535-545 ◽  
Author(s):  
Daikun Jia ◽  
Yi Tong ◽  
Jin Hu
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Initial Decomposition Temperature ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Upper Limit

Flame-retardant rigid polyurethane foams incorporating N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol have been prepared. After adding N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol, the density and compressive strength of the polyurethane foams were seen to decrease. The flame retardancy of the polyurethane foams has been characterized by limiting oxygen index, upper limit–94, and cone calorimeter tests. The polyurethane foam with 2.27 wt% N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol gave a highest limiting oxygen index of 33.4%, and the peak heat release rate of polyurethane foam reduced to 19.5 kW/m2 from 47.6 kW/m2 of PU-0 without N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol. Upper limit–94 revealed N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol did not change the burning rating, and all polyurethane foams had passed V-0 rating. The thermal stability of polyurethane foams has been investigated by thermogravimetric analyzer. N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol significantly increased the initial decomposition temperature of polyurethane foams and their residues. In addition, the morphology of residual char from the flame-retarded polyurethane foams after cone calorimeter tests has also been characterized by digital photographs. The results indicated that N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol significantly enhanced the strength and compatibility of the char layer formed by the polyurethane foams. These results indicate that N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol can improve both the quality and quantity of the char, which has a significant effect on the flame-retardant properties of the foam.

Preparation of microcellular poly(lactic acid) composites foams with improved flame retardancy

2016 ◽  
Vol 53 (1) ◽  
pp. 45-63 ◽  
Author(s):  
Kun Wang ◽  
Jingjing Wang ◽  
Dan Zhao ◽  
Wentao Zhai
Keyword(s):  
Lactic Acid ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Poly Lactic Acid ◽  
Limited Oxygen Index ◽  
Cell Structures ◽  
Phosphorus Containing ◽  
Flame Retardant Properties ◽  
Index Value ◽  
Limited Oxygen

In this study, flame-retardant poly(lactic acid) foams with satisfactory cell structures were prepared by microcellular foaming technology using phosphorus-containing flame retardant and graphene as the charring agent. The introduction of 5–30 wt% flame retardant increased the limited oxygen index value of poly(lactic acid) from 19.0 to 26.5–37.8% and simultaneously increased the foam expansion of poly(lactic acid) foams from 4.4 to 5.8–17.5. In addition, all the prepared poly(lactic acid)/flame-retardant composites passed the UL-94 V-0 rating. The addition of 0.5 wt% graphene increased the limited oxygen index value of poly(lactic acid)/flame-retardant composite with flame-retardant content of 15 wt% from 27.9 to 29.2%, and more graphene additions improved the antidripping behavior of poly(lactic acid) composites. The possible mechanisms of the effects of the resultant cellular structure on the flame-retardant properties of poly(lactic acid) composites were also discussed.

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