Thermal Stability, Smoke Density, and Flame Retardance of Ecotype Bio-Based Flame Retardant Agricultural Waste Bagasse/Epoxy Composites

In the study, agricultural waste bagasse was used as a bio-based flame retardant for reducing the flammability of epoxy. Specifically, an interpenetrating network (IPN) was formed through a ring opening reaction between the hydroxyl functional group of bagasse and the epoxy group of triglycidyl isocyanurate (TGIC), forming Bagasse@TGIC. Next, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) was mixed with Bagasse@TGIC, inducing a reaction between the active hydrogen of DOPO and the epoxy group of TGIC, ultimately forming Bagasse@TGIC@DOPO with an IPN structure. Finally, the novel flame retardant was added to epoxy to create a composite. The integral procedural decomposition temperature (IPDT) of pure epoxy is 619 °C; after the introduction of the 30 wt% flame retardant, the IPDT of the resultant composite material increased to 799 °C, greatly increasing the thermal stability by 29%. After the addition of the Bagasse@TGIC@DOPO flame retardant, the limiting oxygen index increased from 21% for the pure epoxy to 29% for the composite, and the UL-94 rating improved from failing rating for the pure epoxy and V-0 rating for the composite. The Raman spectrum indicated that the addition of Bagasse@TGIC@DOPO IPN substantially increased the biochar yield during the burning process, increasing thermal stability. These results confirmed that the epoxy/Bagasse@TGIC@DOPO composite had substantial flame retarding effects.

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Preparation and Characteristics of an Environmentally Friendly Hyperbranched Flame-Retardant Polyurethane Hybrid Containing Nitrogen, Phosphorus, and Silicon

Polymers ◽

10.3390/polym11040720 ◽

2019 ◽

Vol 11 (4) ◽

pp. 720 ◽

Cited By ~ 4

Author(s):

Chen ◽

Chiang

Keyword(s):

Thermal Stability ◽

Flame Retardant ◽

Hybrid Material ◽

Functional Group ◽

Condensation Reaction ◽

Sol Gel ◽

Decomposition Temperature ◽

Limiting Oxygen Index ◽

Raman Analysis ◽

Ring Opening Reaction

The NCO functional group of 3-isocyanatoproplytriethoxysilane (IPTS) and the OH functional group of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phospha-phenantbrene-10-oxide (DOPO-BQ) were used to conduct an addition reaction. Following completion of the reaction, triglycidyl isocyanurate (TGIC) was introduced to conduct a ring-opening reaction. Subsequently, a sol–gel method was used to initiate a hydrolysis–condensation reaction on TGIC–IPTS–DOPO-BQ to form a hyperbranched nitrogen–phosphorous–silicon (HBNPSi) flame retardant. This flame retardant was incorporated into a polyurethane (PU) matrix to prepare a hybrid material. Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), limiting oxygen index (LOI), UV-VIS spectrophotometry, and Raman analysis were conducted to characterize the structure and analyze the transparency, thermal stability, flame retardancy, and residual char to understand the flame retardant mechanism of the prepared hybrid material. After the flame retardant was added, the maximum degradation rate decreased from −36 to −17 wt.%/min, the integral procedural decomposition temperature (IPDT) increased from 348 to 488 °C, and the char yield increased from 0.7 to 8.1 wt.%. The aforementioned results verified that the thermal stability of PU can be improved after adding HBNPSi. The LOI analysis indicated that the pristine PU was flammable because the LOI of pristine PU was only 19. When the content of added HBNPSi was 40%, the LOI value was 26; thus the PU hybrid became nonflammable.

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Preparation, Characterization, Thermal, and Flame-Retardant Properties of Green Silicon-Containing Epoxy/Functionalized Graphene Nanosheets Composites

Journal of Nanomaterials ◽

10.1155/2013/747963 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 9

Author(s):

Ming-Yuan Shen ◽

Chen-Feng Kuan ◽

Hsu-Chiang Kuan ◽

Chia-Hsun Chen ◽

Jia-Hong Wang ◽

...

Keyword(s):

Thermal Stability ◽

Flame Retardant ◽

Graphene Nanosheets ◽

Sol Gel ◽

Decomposition Temperature ◽

Gravimetric Analysis ◽

Limiting Oxygen Index ◽

Integral Procedure ◽

Flame Retardant Properties ◽

Modified Epoxy

In this investigation, silane was grafted onto the surface of graphene nanosheets (GNSs) through free radical reactions, to form Si-O-Et functional groups that can undergo the sol-gel reaction. To improve the compatibility between the polymer matrix and the fillers, epoxy monomer was modified using a silane coupling agent; then, the functionalized GNSs were added to the modified epoxy to improve the thermal stability and strengthen the flame-retardant character of the composites. High-resolution X-ray photoelectron spectrometry reveals that when the double bonds in VTES are grafted to the surfaces of GNSs. Solid-state 29Si nuclear magnetic resonance presents that the distribution of the signal associated with the T3structure is wide and significant, indicating that the functionalization reaction of the silicone in the modified epoxy and VTES-GNSs increases the network-like character of the structures. Thermal gravimetric analysis, the integral procedure decomposition temperature, and limiting oxygen index demonstrate that the GNSs composites that contained silicon had a higher thermal stability and stronger flame-retardant character than pure epoxy. The dynamic storage modulus of all of the m-GNSs containing composites was significantly higher than that of the control epoxy, and the modulus of the composites increased with the concentration of m-GNSs.

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An Effective Method for Preparation of Liquid Phosphoric Anhydride and Its Application in Flame Retardant Epoxy Resin

Materials ◽

10.3390/ma14092205 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2205

Author(s):

Qian Li ◽

Yujie Li ◽

Yifan Chen ◽

Qiang Wu ◽

Siqun Wang

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Epoxy Resins ◽

Oxygen Index ◽

Decomposition Temperature ◽

Ease Of Use ◽

Limiting Oxygen Index ◽

Good Thermal Stability ◽

Low Viscosity ◽

The Impact

A novel liquid phosphorous-containing flame retardant anhydride (LPFA) with low viscosity was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and methyl tetrahydrophthalic anhydride (MeTHPA) and further cured with bisphenol-A epoxy resin E-51 for the preparation of the flame retardant epoxy resins. Both Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) measurements revealed the successful incorporation of DOPO on the molecular chains of MeTHPA through chemical reaction. The oxygen index analysis showed that the LPFA-cured epoxy resin exhibited excellent flame retardant performance, and the corresponding limiting oxygen index (LOI) value could reach 31.2%. The UL-94V-0 rating was achieved for the flame retardant epoxy resin with the phosphorus content of 2.7%. With the addition of LPFA, the impact strength of the cured epoxy resins remained almost unchanged, but the flexural strength gradually increased. Meanwhile, all the epoxy resins showed good thermal stability. The glass transition temperature (Tg) and thermal decomposition temperature (Td) of epoxy resin cured by LPFA decreased slightly compared with that of MeTHPA-cured epoxy resin. Based on such excellent flame retardancy, low viscosity at room temperature and ease of use, LPFA showed potential as an appropriate curing agent in the field of electrical insulation materials.

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A Study on the Synthesis, Curing Behavior and Flame Retardance of a Novel Flame Retardant Curing Agent for Epoxy Resin

Polymers ◽

10.3390/polym14020245 ◽

2022 ◽

Vol 14 (2) ◽

pp. 245

Author(s):

Yong Sun ◽

Yongli Peng ◽

Yajiao Zhang

Keyword(s):

Flame Retardant ◽

Epoxy Resin ◽

Decomposition Temperature ◽

Isothermal Kinetics ◽

Flame Retardance ◽

Curing Agent ◽

Initial Decomposition Temperature ◽

Limiting Oxygen Index ◽

Epoxy Resin System ◽

Dsc Method

In this work, a flame retardant curing agent (DOPO-MAC) composed of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and methyl acrylamide (MAC) was synthesized successfully, and the structure of the compound was characterized by FT-IR and 1H-NMR. The non-isothermal kinetics of the epoxy resin/DOPO-MAC system with 1% phosphorus was studied by non-isothermal DSC method. The activation energy of the reaction (Ea), about 46 kJ/mol, was calculated by Kissinger and Ozawa method, indicating that the curing reaction was easy to carry out. The flame retardancy of the epoxy resin system was analyzed by vertical combustion test (UL94) and limiting oxygen index (LOI) test. The results showed that epoxy resin (EP) with 1% phosphorus successfully passed a UL-94 V-0 rating, and the LOI value increased along with the increasing of phosphorus content. It confirmed that DOPO-MAC possessed excellent flame retardance and higher curing reactivity. Moreover, the thermal stability of EP materials was also investigated by TGA. With the DOPO-MAC added, the residual mass of EP materials increased remarkably although the initial decomposition temperature decreased slightly.

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Synthesis and Application of a Novel Intumescent Flame Retardant Containing Ferrocenyl

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1033-1034.931 ◽

2014 ◽

Vol 1033-1034 ◽

pp. 931-936

Author(s):

Cong Yan Chen ◽

Rui Lan Fan ◽

Guan Qun Yun

Keyword(s):

Thermal Stability ◽

Flame Retardant ◽

Flame Retardants ◽

Intumescent Flame Retardant ◽

Limiting Oxygen Index ◽

Good Thermal Stability ◽

H Nmr ◽

Positive Effect ◽

Thermal Stability Of ◽

Phosphate Groups

A novel intumescent flame retardant (IFR) containing ferrocene and caged bicyclic phosphate groups, 1-oxo-4-[4'-(ferrocene carboxylic acid phenyl ester)] amide-2, 6, 7-trioxa-1-phosphabicyclo- [2.2.2] octane (PFAM), was successfully synthesized. The synthesized PFAM were added to flammable polyurethane (PU) as flame retardants and smoke suppressants. The structure of PFAM was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR) and elemental analysis. Thermal stability of PFAM was tested by themogravimetric analysis (TGA). The results revealed that PFAM had good thermal stability and high char weight, the char weight up to 54% at 600 °C. Flammability properties of PU/PFAM composites were investigated by limiting oxygen index (LOI) test and UL-94 test, respectively. The results of LOI tests showed that the addition of PFAM enhanced flame retardancy of PU. When the content of PFAM reaches to 3%, the LOI value is 22.2. The morphologies of the char for PU and PU/3% PFAM composite can be obtained after LOI testing were examined by SEM. The results demonstrated that PFAM could promote to form the compact and dense intumescent char layer. Experiments showed that, the PFAM application of polyurethane showed positive effect.

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Effects of Tung Oil-Based Polyols on the Thermal Stability, Flame Retardancy, and Mechanical Properties of Rigid Polyurethane Foam

Polymers ◽

10.3390/polym11010045 ◽

2018 ◽

Vol 11 (1) ◽

pp. 45 ◽

Cited By ~ 10

Author(s):

Wei Zhou ◽

Caiying Bo ◽

Puyou Jia ◽

Yonghong Zhou ◽

Meng Zhang

Keyword(s):

Thermal Stability ◽

Polyurethane Foam ◽

Flame Retardancy ◽

Covalent Bond ◽

Rigid Polyurethane Foam ◽

Limiting Oxygen Index ◽

Sem Micrographs ◽

Tung Oil ◽

Char Layer ◽

Ring Opening Reaction

A phosphorus-containing tung oil-based polyol (PTOP) and a silicon-containing tung oil-based polyol (PTOSi) were each efficiently prepared by attaching 9,10-dihydro-9-oxa-10-phosphaphenanthrene (DOPO) and dihydroxydiphenylsilane (DPSD) directly, respectively, to the epoxidized monoglyceride of tung oil (EGTO) through a ring-opening reaction. The two new polyols were used in the formation of rigid polyurethane foam (RPUF), which displayed great thermal stability and excellent flame retardancy performance. The limiting oxygen index (LOI) value of RPUF containing 80 wt % PTOP and 80 wt % PTOSi was 24.0% and 23.4%, respectively. Fourier transfer infrared (FTIR), Nuclear Magnetic Resonance (NMR) and thermogravimetric (TG) analysis revealed that DOPO and DPSD are linked to EGTO by a covalent bond. Interestingly, PTOP and PTOSi had opposite effects on Tg and the compressive strength of RPUF, where, with the appropriate loading, the compressive strengths were 0.82 MPa and 0.25 MPa, respectively. At a higher loading of PTOP and PTOSi, the thermal conductivity of RPUF increased while the RPUF density decreased. The scanning electron microscope (SEM) micrographs showed that the size and closed areas of the RPUF cells were regular. SEM micrographs of the char after combustion showed that the char layer was compact and dense. The enhanced flame retardancy of RPUF resulted from the barrier effect of the char layer, which was covered with incombustible substance.

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Influence of silicon dioxide addition and processing methods on structure, thermal stability and flame retardancy of EVA/NR blend nanocomposite foams

Progress in Rubber Plastics and Recycling Technology ◽

10.1177/1477760620953437 ◽

2020 ◽

pp. 147776062095343

Author(s):

Alif Walong ◽

Bencha Thongnuanchan ◽

Tadamoto Sakai ◽

Natinee Lopattananon

Keyword(s):

Thermal Stability ◽

Silicon Dioxide ◽

Flame Retardant ◽

Flame Retardancy ◽

Layered Silicate ◽

Melt Mixing ◽

Limiting Oxygen Index ◽

Char Layer ◽

Nanocomposite Foams ◽

Silicon Based

Rubber nanocomposite foams based on 60/40 ethylene vinyl acetate (EVA)/natural rubber (NR) were melt-mixed with flame retardant silicon dioxide (SiO2) (20 parts per hundred rubber, phr), and foamed by compression molding process. In this study, the effect of mixing phenomena of SiO2 through two different compounding techniques such as direct mixing (DM) and phase selective mixing (PSM) methods on structure, thermal stability, combustility and flame retardancy of EVA/NR blend nanocomposite foams were investigated. DM method is a melt mixing of EVA, NR, layered silicate and SiO2, followed by foaming. PSM is a new method based on pre-mixing EVA with SiO2, then melt mixing of EVA/SiO2 masterbatch with NR and layered silicate, and finally foaming. Based on TEM technique, it was found that the SiO2 was exclusively located in dispersed NR phase for the sample prepared by DM method, and the SiO2 was preferably dispersed in continuous EVA matrix when PSM method was employed. However, the different mixing methods did not significantly alter their cellular structures. The thermal stability and char residue content of foamed samples with SiO2 increased obviously when compared with those of corresponding foams without SiO2. The results based on limiting oxygen index (LOI) test and oxygen bomb calorimetry indicated that the foams combined with SiO2 had better combustion resistance and flame retardancy due to barrier effect of thermally stable silicon-based char layer. Further, the SiO2 filled foamed system obtained from the PSM method showed a higher degree of improvement in thermal stability, combustion resistance and flame retardancy than that of DM method because the homogeneous dispersion of SiO2 in EVA matrix rather than the selective dispersion in NR phase. This resulted in the continuity of flame retardant EVA/SiO2 phase in the 60/40 EVA/NR nanocomposite foams, which exerted more efficient fire barrier of the silicon-based char layer.

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Flammability and thermal properties of cotton fabrics modified with a novel flame retardant containing triazine and phosphorus components

Textile Research Journal ◽

10.1177/0040517516652349 ◽

2016 ◽

Vol 87 (11) ◽

pp. 1367-1376 ◽

Cited By ~ 20

Author(s):

Chaohong Dong ◽

Zhou Lu ◽

Peng Wang ◽

Ping Zhu ◽

Xuechao Li ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Cotton Fabric ◽

Flame Retardancy ◽

Decomposition Temperature ◽

Cotton Fabrics ◽

Cone Calorimetry ◽

Limiting Oxygen Index ◽

Untreated Cotton ◽

Index Value

A novel formaldehyde-free flame retardant containing phosphorus and dichlorotriazine components (CTAP) for cotton fabrics was synthesized. As an active group, the dichlorotriazine could react with cotton fabric via covalent reaction. The addition of 20.7 wt% CTAP into the cotton fabric obtained a high limiting oxygen index value of 31.5%, which was 13.5% higher than the pure cotton fabric. The results of heat release rate, total heat release and effective heat combustion indicated that CTAP effectively imparted flame retardancy to cotton fabric by the cone calorimetry test. With respect to the untreated cotton fabrics, the treated cotton fabrics degraded at lower decomposition temperature and form a consistent and compact char layer, which could be observed by thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the untreated cotton fabrics, CTAP performed an effective role in flame retardancy for treated cotton fabrics. Meanwhile, it stimulated the formation of char and promoted the thermal stability of treated cotton fabrics during combustion.

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Preparation of lignin–silica hybrids and its application in intumescent flame-retardant poly(lactic acid) system

High Performance Polymers ◽

10.1177/0954008312451476 ◽

2012 ◽

Vol 24 (8) ◽

pp. 738-746 ◽

Cited By ~ 41

Author(s):

Rui Zhang ◽

Xifu Xiao ◽

Qilong Tai ◽

Hua Huang ◽

Jian Yang ◽

...

Keyword(s):

Thermal Stability ◽

Lactic Acid ◽

Flame Retardant ◽

Flame Retardancy ◽

Photoelectron Spectroscopy ◽

Intumescent Flame Retardant ◽

Poly Lactic Acid ◽

Limiting Oxygen Index ◽

Silica Hybrids ◽

Thermal Stability Of

Lignin–silica hybrids (LSHs) were prepared by sol–gel method and characterized by Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). LSH and ammonium polyphosphate (APP) were added into poly(lactic acid) (PLA) as a novel intumescent flame-retardant (IFR) system to improve the flame retardancy of PLA. The flame-retardant effect of APP and LSH in PLA was studied using limiting oxygen index (LOI), vertical burning (UL-94) tests and cone calorimeter. The thermal stability of PLA/APP/LSH composites was evaluated by thermogravimetric analysis (TGA). Additionally, the morphology and components of char residues of the IFR-PLA composites were investigated by SEM and XPS. With the addition of APP/LSH to PLA system, the morphology of the char residue has obviously changed. Compared with PLA/APP and PLA/APP/lignin, a continuous and dense intumescent charring layer with more phosphor in PLA composites is formed, which exhibits better flame retardancy. All the results show that the combination of APP and LSH can improve the flame-retardant property and increase the thermal stability of PLA composites greatly.

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