Functionalization of Graphene and Its Influence on Mechanical Properties and Flame Retardancy of Jute/Poly(lactic acid) Composite

2019 ◽  
Vol 19 (11) ◽  
pp. 7074-7082 ◽  
Author(s):  
Tao Yu ◽  
Changqing Hu ◽  
Yan Li
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
Oxygen Index ◽  
Poly Lactic Acid ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Matrix Toughness ◽  
Modified Graphene

In this work, 9,10-dihydro-9-oxa-phosphaphenanthrene-10-oxide (DOPO) was covalently grafted onto the surface of graphene to get modified graphene (G-DOPO) firstly. The mechanical properties and flame retardancy of jute/poly(lactic acid) (PLA) composite with G-DOPO were studied. According to Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), it was confirmed that DOPO was grafted on the surface of graphene successfully. Thermogravimetric analysis (TGA) results demonstrated that the residue char of the composites increased with the addition of G-DOPO. The total heat release (THR) of the composite was significantly reduced and the limiting oxygen index (LOI) increased after adding G-DOPO into the composite. Moreover, the mechanical properties results showed that the comprehensive effects of G-DOPO on the interface enhancement and matrix toughness were found.

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

2012 ◽  
Vol 24 (8) ◽  
pp. 738-746 ◽  
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.

scholarly journals Effect of a Novel Flame Retardant on the Mechanical, Thermal and Combustion Properties of Poly(Lactic Acid)

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2407
Author(s):  
Mingjun Niu ◽  
Zhongzhou Zhang ◽  
Zizhen Wei ◽  
Wanjie Wang
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Flame Retardant ◽  
Testing Machine ◽  
Poly Lactic Acid ◽  
Limiting Oxygen Index ◽  
Biobased Materials ◽  
Cone Calorimeter Test ◽  
Combustion Properties ◽  
Ul 94

Poly(lactic) acid (PLA) is one of the most promising biobased materials, but its inherent flammability limits its applications. A novel flame retardant hexa-(DOPO-hydroxymethylphenoxy-dihydroxybiphenyl)-cyclotriphosphazene (HABP-DOPO) for PLA was prepared by bonding 9,10-dihydro-9-oxy-10-phosphaphenanthrene-10-oxide (DOPO) to cyclotriphosphazene. The morphologies, mechanical properties, thermal stability and burning behaviors of PLA/HABP-DOPO blends were investigated using a scanning electron microscope (SEM), a universal mechanical testing machine, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), limiting oxygen index (LOI), vertical burning (UL-94) and a cone calorimeter test (CCT). The LOI value reached 28.5% and UL-94 could pass V-0 for the PLA blend containing 25 wt% HABP-DOPO. A significant improvement in fire retardant performance was observed for PLA/HABP-DOPO blends. PLA/HABP-DOPO blends exhibited balanced mechanical properties. The flame retardant mechanism of PLA/HABP-DOPO blends was evaluated.

scholarly journals Karakterisasi Nanokomposit Poly(Lactic Acid)-Spent Bleaching Earth Regenerasi Termodifikasi

KOVALEN ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 90-98
Author(s):  
Tika Paramitha ◽  
Johnner P. Sitompul
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Bleaching Earth ◽  
Renewable Resource ◽  
Urea Solution ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Universal Testing

Development of renewable resource-based polymers attracts attention to solve environmental problems due to the build up of polymer (plastic). Poly(lactic acid) (PLA) is one of the most widely used polymers which have good biodegradability and processability. The addition of fillers to the PLA matrix aims to improve the characteristics of the PLA, such as mechanical properties of nanocomposites of PLA. Thus, PLA can be use as substitution of fossil fuel-based polymer. Spent Bleaching Earth (SBE) can be used as a filler after regeneration process. SBE was extracted and oxidized to take its oil content. Then, SBE was modified with urea solution to increase the interlayer distance. In this study, structure of nanocomposites was characterized using X-Ray Diffraction and mechanical properties of nanocomposites were characterized using Universal Testing Machines. X-Ray Diffraction characterization results show that PLA-SBE nanocomposite and PLA-modified regenerated SBE nanocomposites do not form new peaks, so SBE and modified regenerated SBE is intercalated and partially exfoliated in the PLA matrix. The degree of intercalation/exfoliation is indicated by the results of characterization of mechanical properties. The mechanical properties of PLA-SBE nanocomposite are lower than neat PLA, whereas the mechanical properties of PLA-modified regenerated SBE nanocomposites are higher than neat PLA. The best mechanical properties of nanocomposites were obtained for PLA-5% modified regenerated SBE, with elongation and tensile strength, 3.26%, and 42.22 MPa, respectively. Keywords: nanocomposites, poly(lactic acid), regeneration, spent bleaching earth

scholarly journals Flame Retardancy Properties and Physicochemical Characteristics of Polyurea-Based Coatings Containing Flame Retardants Based on Aluminum Hydroxide, Resorcinol Bis(Diphenyl Phosphate), and Tris Chloropropyl Phosphate

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5168
Author(s):  
Wojciech Dukarski ◽  
Piotr Krzyżanowski ◽  
Marcin Gonsior ◽  
Iwona Rykowska
Keyword(s):  
Mechanical Properties ◽  
Aluminum Hydroxide ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Good Alternative ◽  
Physicochemical Characteristics ◽  
Limiting Oxygen Index ◽  
Diphenyl Phosphate ◽  
Further Development

Polyurea is a synthetic material made by the reaction of isocyanate and polymer blend-containing amines. Due to its outstanding mechanical properties and fast curing, polyurea-based coatings have found dozens of applications, including waterproofing and anti-corrosion coatings. Further development of this material can create a flame-retardant product, a good alternative for common products available on the market, such as intumescent coatings. To improve the flame retardancy of polyurea, several flame retardants were investigated. The influence of aluminum hydroxide, resorcinol bis(diphenyl phosphate) (RDP), and tris chloropropyl phosphate (TCPP) on flame retardancy and morphology was studied. The following methods were used: infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, limiting oxygen index, and tensile strength. The examinations mentioned above showed the improvement of flame-retardancy of polyurea for two products: chlorinated organophosphate and organophosphate. Nevertheless, using the chlorinated organophosphate additive caused a rapid deterioration of mechanical properties.

scholarly journals Effects of chemical pre-treatment on structure and property of polyacrylonitrile based pre-oxidized fibers

2020 ◽  
Vol 15 ◽  
pp. 155892501989894
Author(s):  
Xiaolu Sun ◽  
Jiayin Song ◽  
Jin Zhang ◽  
Jingyan Liu ◽  
Huizhen Ke ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Heat Release ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Energy Dispersive Spectrometer ◽  
Chemical Compositions ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Pre Treatment

Polyacrylonitrile-based pre-oxidized fibers with improved thermal stability, flame retardant, and mechanical properties were made from the pristine polyacrylonitrile fibers through chemical pretreatment followed by pre-oxidation in air. The morphological structure of the polyacrylonitrile-based pre-oxidized fibers was investigated by Fourier transfer infrared spectra, X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectrometer. The changes of characteristic functional groups and chemical compositions confirmed the successful modification of the polyacrylonitrile fibers during pre-treatment. The grooves and cracks on the surface of polyacrylonitrile-based pre-oxidized fibers were remarkably decreased in comparison with that of pristine polyacrylonitrile fibers. The evolution of crystalline structure of the polyacrylonitrile fibers proved the occurrence of cyclization reactions during pre-oxidation. Meanwhile, thermal stability, flame retardant, and mechanical properties of polyacrylonitrile-based pre-oxidized fibers were also investigated by thermogravimetric analyzer, oxygen index meter, micro combustion calorimeter, and single fiber tensile tester, respectively. The results demonstrated that the polyacrylonitrile-based pre-oxidized fibers initially pre-treated by hydroxylamine hydrochloride, followed by monoethanolamine, had a high limiting oxygen index of 40.1 and breaking strength of 2.03 cN/dtex. The peak of heat release rate and total heat release of polyacrylonitrile-based pre-oxidized fibers decreased significantly while its charred residues increased, contributing to the improved flame retardant property.

Investigation of nickel ammonia phosphate with different morphologies as a new high-efficiency flame retardant for epoxy resin

2019 ◽  
Vol 32 (4) ◽  
pp. 359-370 ◽  
Author(s):  
Weiwei Zhang ◽  
Hongjuan Wu ◽  
Weihua Meng ◽  
Jiahe Li ◽  
Yumeng Cui ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Ammonium Phosphate ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
The Matrix

Nanowires, nanosheets, and microflowers of nickel ammonium phosphate (NiNH4PO4·H2O) were synthesized by a mixed solvothermal method and used to improve the flame retardancy of epoxy resin (EP). The solvent concentration and surfactant content were found to play a key role in nucleation and growth of NiNH4PO4·H2O. The structure of NiNH4PO4·H2O was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The flame retardancy, thermostability, mechanical properties, and flame retardancy mechanism of EP/NiNH4PO4·H2O composites were analyzed using the limiting oxygen index (LOI), cone calorimetry (Cone), mechanical property tests, thermogravimetric analysis, and thermogravimetric–Fourier transform infrared spectroscopy. The results indicated that NiNH4PO4·H2O has proper thermal stability and greatly improves the flame retardancy of EP. The nanosheets outperformed the other morphologies; the EP/5% NiNH4PO4·H2O nanosheets have an LOI of 35.2%, which exceeds that of pure EP (24.7%). Furthermore, Cone showed that these nanosheets have the lowest peak heat release rate and peak smoke production rate, which are 69.1% and 36.5% lower than those of pure EP, respectively. NiNH4PO4·H2O can promote the formation of a stable char layer and release nonflammable gases, thus protecting the matrix by preventing heat and oxygen transfer and reducing the concentration of combustible gas. NiNH4PO4·H2O is expected to serve as a new high-efficiency flame retardant for EP.

Flammability and thermal properties of modified carbon nanotubes in poly(lactic acid)

2018 ◽  
Vol 32 (8) ◽  
pp. 1107-1122 ◽  
Author(s):  
Chao Guo ◽  
Fei Xin ◽  
Congcong Zhai ◽  
Yu Chen
Keyword(s):  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Flame Retardancy ◽  
Mass Loss Rate ◽  
Covalent Bond ◽  
Poly Lactic Acid ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
Multi Walled Carbon Nanotubes ◽  
Modified Carbon Nanotubes

The multi-walled carbon nanotubes (CNTs) were modified using phosphaphenanthrene compounds (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)) and vinyl triethoxy silane (VTES) by covalent bond. The DOPO- and VTES-treated CNTs were named DVCNT, and the structure was characterized by Fourier transform infrared, thermogravimetric analysis, and transmission electron microscopy. Nanocomposites were prepared by adding CNTs or DVCNT to poly(lactic acid) (PLA), and the flame retardancy was examined by determination of limiting oxygen index (LOI), vertical burning (UL94), and cone calorimetry. Results reveal that the LOI of PLA/DVCNT_4% composites was increased to 26.6 and prevents dripping of PLA in some level, and DVCNT can significantly reduce heat release rate and mass loss rate during combustion, which indicate that DVCNT can improve the dispersibility of the CNTs in the polymer composites and hence enhance the flame retardancy simultaneously.

scholarly journals Mechanical and flammability properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends and nanocomposites: Effects of compatibilizer and graphene

2018 ◽  
Vol 14 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Nilesh Kumar Shrivastava ◽  
Ooi Shu Wooi ◽  
Azman Hassan ◽  
Ibrahim Mohammed Inuwa
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Flame Retardancy ◽  
Testing Machine ◽  
High Strength ◽  
Poly Lactic Acid ◽  
Limiting Oxygen Index ◽  
Morphological Studies ◽  
Impact Tester ◽  
Ul 94

Poly(lactic acid) (PLA)/polybutylene adipate co-terephthalate (PBAT) blends were prepared by melt blending and compatibilized by glycidyl methacrylate (GMA). The effect of graphene nanoplatelets (GNP) on these compatibilized blends were investigated by incorporating GNP at different content. The formulated blend and nanocomposites were characterized for mechanical, morphological, thermal and flammability properties by using universal testing machine, impact tester, field emission scanning electron microscope (FESEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), limiting oxygen index (LOI) and UL-94 respectively. The incorporation of 8 phr GMA into PLA/PBAT (75:25) blend as a compatibilizer results in a significant increase in impact strength (more than 14 times higher) compared to the uncompatibilized blend. Young's modulus and tensile strength of compatibilized PLA/PBAT nanocomposites increased upon addition of GNP and reached maximum values at 4 phr before decreasing slightly. However, impact strength decreased with increasing GNP contents. The thermal stability and the flame retardancy of the GNP reinforced blend nanocomposites were also improved with an increase in nanofiller content and the maximum values for the nanocomposites were achieved at 6 phr. Interestingly, the nanocomposites samples showed a UL-94 rating of V0 at 4 and 6 phr of GNP. Morphological studies using FESEM showed the GNP were evenly distributed and dispersed in the PLA/PBAT nanocomposites. The current methodology to prepare PLA/PBAT blend nanocomposite is an economical way to produce high strength biodegradable polymer which also has good flame retardancy.

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