scholarly journals Flame-Retardant Wood Composites Based on Immobilizing with Chitosan/Sodium Phytate/Nano-TiO2-ZnO Coatings via Layer-by-Layer Self-Assembly

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 296 ◽  
Author(s):  
Lin Zhou ◽  
Yanchun Fu
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Self Assembly ◽  
Composite Coatings ◽  
Wood Products ◽  
Layer By Layer ◽  
Zno Nanoparticle ◽  
Nano Tio2 ◽  
Limiting Oxygen Index ◽  
Sodium Phytate

Composite coatings of inorganic nanomaterials with polyelectrolytes are promising materials for wood modification. Endowing wood with flame retardancy behavior can not only broaden the range of applications of wood, but also improve the safety of wood products. In this work, chitosan/sodium phytate/TiO2-ZnO nanoparticle (CH/SP/nano-TiO2-ZnO) composite coatings were coated on wood surface through layer-by-layer self-assembly. The morphology and chemical composition of the modified wood samples were analyzed using scanning electron microscopy and energy dispersive spectrometry. The thermal degradation properties and flame retardancy of the samples treated with different assembly structures were observed by thermogravimetric analysis, limiting oxygen test, and combustion test. Due to the presence of an effective intumescent flame retardant system and a physical barrier, the CH/SP/nano-TiO2-ZnO coatings exhibited the best flame retardant performance and required only approximately six seconds for self-extinguishing. The coated samples had a limiting oxygen index of 8.4% greater than the original wood.

scholarly journals Layer-by-layer assembly flame-retardant and anti-dripping treatment of polyethylene terephthalate fabrics

2019 ◽  
Vol 14 ◽  
pp. 155892501987030
Author(s):  
Yinchun Fang ◽  
Xinhua Liu ◽  
Cuie Wang
Keyword(s):  
Flame Retardant ◽  
Polyethylene Terephthalate ◽  
Flame Retardancy ◽  
Alkali Treatment ◽  
Ammonium Polyphosphate ◽  
Layer By Layer ◽  
Limiting Oxygen Index ◽  
Layer By Layer Assembly ◽  
Branched Polyethylenimine ◽  
Layer Assembly

Layer-by-layer assembly is a simple and effective method which has been widely studied to improve the flame retardancy of textiles in recent years. In this article, flame-retardant and anti-dripping polyethylene terephthalate fabrics were successfully prepared by layer-by-layer assembly branched polyethylenimine and ammonium polyphosphate on their surface. The results of limiting oxygen index values and vertical burning test revealed that the flame retardancy and anti-dripping performance of polyethylene terephthalate fabrics were improved after the layer-by-layer assembly treatment; especially, the dripping phenomenon was eliminated when the number of branched polyethylenimine/ammonium polyphosphate bilayers was over 10. The influence of alkali treatment of polyethylene terephthalate fabrics before layer-by-layer assembly was also investigated. The results showed that alkali treatment of the polyethylene terephthalate fabrics would promote the combination of polyethylene terephthalate fabrics and the charged flame retardants indicating better flame retardancy. The results of thermogravimetric analysis revealed that layer-by-layer assembly treatment of polyethylene terephthalate fabrics would promote char formation both under the nitrogen atmosphere and under the air atmosphere which may act through condensed phase action. The scanning electron microscopy images of the char residues revealed that the layer-by-layer assembly treatment of polyethylene terephthalate fabrics would promote the formation of a compact and intact char residue, which was beneficial for the improvement of flame retardancy and anti-dripping performance. This research would provide the experimental basis for the effective flame retardancy and anti-dripping performance of polyethylene terephthalate fabric.

scholarly journals Surface Properties of Spray-Assisted Layer-By-Layer ElectroStatic Self-Assembly Treated Wooden Take-Off Board

2021 ◽  
Vol 11 (2) ◽  
pp. 836
Author(s):  
Yi Wan ◽  
Sijie Hou ◽  
Mengyao Guo ◽  
Yanchun Fu
Keyword(s):  
Self Assembly ◽  
Treated Wood ◽  
Contact Angles ◽  
Water Repellent ◽  
Layer By Layer ◽  
Air Exposure ◽  
Limiting Oxygen Index ◽  
Sodium Phytate ◽  
Static Contact ◽  
Combustion Tests

Wooden take-off board is easy to crack, deform, discolor, and decay when it is used outdoors, which not only increases maintenance costs but also reduces its service life. Multifunctional coatings with UV-resistant, water-repellent, and flame-retardant properties were successfully obtained on the surface of a wooden take-off board substrate by spray-assisted layer-by-layer self-assembly. The coatings consisted of positively-charged chitosan, Al (OH)3, and negatively-charged sodium phytate through electrostatic adsorption several times. The treated wood exhibited high UV resistance, and the color remained constant after 720 hours of ultraviolet irradiation. The wettability of the wood surface after treatment became superhydrophobic, with initial static contact angles as high as 140°. In addition, limiting oxygen index and air exposure combustion tests were used to verify that chitosan, sodium phytate, and aluminum hydroxide could synergistically confer significant fire resistance to modified wood.

scholarly journals Preparation and Synergistic Effect of Chitosan/Sodium Phytate/MgO Nanoparticle Fire-Retardant Coatings on Wood Substrate through Layer-By-Layer Self-Assembly

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 848 ◽  
Author(s):  
Feiyue Zhao ◽  
Tingli Tang ◽  
Sijie Hou ◽  
Yanchun Fu
Keyword(s):  
Self Assembly ◽  
Energy Dispersive Spectrometry ◽  
Oxygen Index ◽  
Fire Retardant ◽  
Layer By Layer ◽  
Wood Substrate ◽  
Limiting Oxygen Index ◽  
Mgo Nanoparticles ◽  
Sodium Phytate ◽  
Mgo Nanoparticle

Fire-retardant chitosan/sodium phytate/MgO nanoparticle (CH/SP/nano-MgO) coatings were loaded on a wood substrate via electrostatic layer-by-layer self-assembly and characterized by scanning electron microscopy and energy-dispersive spectrometry. The flammability and thermal degradation of the original wood and wood samples treated with chitosan, chitosan/sodium phytate, chitosan/sodium phytate/MgO nanoparticles were studied by limiting oxygen index (LOI), exposure combustion experiments and thermogravimetric analysis (TGA), respectively. The CH/SP/nano-MgO coating served as an intumescent fire-retardant system that created a physical protection cover and exhibited the best fire retardant performance. The LOI value was 30.2% and required approximately 16–17 s to self-extinguish when exposed to air. The TGA curves also showed that char formation protected the wood from combustion.

scholarly journals Layer-by-Layer Self-Assembly Composite Coatings for Improved Corrosion and Wear Resistance of Mg Alloy for Biomedical Applications

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 515
Author(s):  
Tongfang Liu ◽  
Song Rui ◽  
Sheng Li
Keyword(s):  
Wear Resistance ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Composite Coatings ◽  
Covalent Bond ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Layer By Layer ◽  
Corrosion Propagation ◽  
Chemical Linkage

Mg alloys are promising biomedical metal due to their natural degradability, good processability, and favorable mechanical properties. However, the poor corrosion resistance limits their further clinical applications. In this study, the combined strategies of surface chemical treatment and layer-by-layer self-assembly were used to prepare composite coatings on Mg alloys to improve the biocorrosion resistance. Specially, alkalized AZ91 Mg alloy generated chemical linkage with silane via Si–O–Mg covalent bond at the interface. Subsequently, Si–OH group from silane formed a crosslinked silane layer by Si–O–Si network. Further chemical assembly with graphene oxide (GO), lengthened the diffusion pathway of corrosive medium. The chemically assembled composite coatings could firmly bond to Mg alloy substrate, which persistently and effectively acted as compact barriers against corrosion propagation. Improved biocorrosion resistance of AZ91 Mg alloy with self-assembly composite coatings of silane/GO was subsequently confirmed by immersion tests. Besides, the Mg alloy exhibited good wear resistance due to outside layer of GO with a lubricant effect. Cell viability of higher than 75% had also been found for the alloy with self-assembly composite coatings, which showed good cytocompatibility.

Fabrication of montmorillonite and titanate nanotube based coatings via layer-by-layer self-assembly method to enhance the thermal stability, flame retardancy and ultraviolet protection of polyethylene terephthalate (PET) fabric

RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 53625-53634 ◽  
Author(s):  
Ying Pan ◽  
Wei Wang ◽  
Haifeng Pan ◽  
Jing Zhan ◽  
Yuan Hu
Keyword(s):  
Thermal Stability ◽  
Polyethylene Terephthalate ◽  
Flame Retardancy ◽  
Self Assembly ◽  
Layer By Layer ◽  
Pet Fabric ◽  
Thermal Oxidative Stability ◽  
Titanate Nanotube ◽  
Assembly Method ◽  
Ultraviolet Protection

Montmorillonite and titanate nanotube based coatings have been prepared through LbL self-assembly method, in order to enhance the thermal and thermal-oxidative stability, flame retardancy and UV protection of polyethylene terephthalate fabric.

scholarly journals Fabrication of thermo-regulating cotton fabric with enhanced flame retardancy via layer-by-layer assembly

2021 ◽  
Author(s):  
Yunbo Chen ◽  
Xiangyu Zhu ◽  
Xiang Li ◽  
Bijia Wang ◽  
Zhiping Mao ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
High Performance ◽  
Cotton Fabrics ◽  
Melting Enthalpy ◽  
Residual Carbon ◽  
Layer By Layer ◽  
Scanning Calorimetry ◽  
Infrared Thermal Imaging ◽  
Limiting Oxygen Index ◽  
Lbl Assembly

Abstract The lack of thermo-regulation functionality and high flammability of cotton fabrics greatly restrict their application in high-performance fields. Herein, we report a versatile layer-by-layer (LbL) assembly strategy for introducing to cotton fabrics a multilayered coating consisted of phase change microcapsules and ammonium polyphosphate, endowing them with thermo-regulating and flame retardancy. The coated fabrics were characterized by limiting oxygen index (LOI), scanning electron microscopy (SEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and infrared thermal imaging. The fabric deposited with 20 bilayers (MCPM/APP-20) showed improved flame retardancy with a LOI of 24.4% and residual carbon of 34.24%. It also shows a melting enthalpy of 30.16 J/g, which transferred to a temperature difference of 6.4 ℃ compared with pristine cotton. The functional endowed by the LbL assembly was reasonably durable, with melting enthalpy and residual carbon of MPCM/APP-20 reduced to 17.14 J/g and 19.82% after 30 laundering cycles. These results suggest that LbL assembly was a convenient way for functionalization of cotton fabrics.

Molecular Composite Coatings on Nafion Using Layer-by-Layer Self-Assembly

2015 ◽  
Vol 7 (19) ◽  
pp. 10365-10373 ◽  
Author(s):  
Christophe J. Lefaux ◽  
Byoung-Suhk Kim ◽  
Narayanan Venkat ◽  
Patrick T. Mather
Keyword(s):  
Self Assembly ◽  
Composite Coatings ◽  
Layer By Layer

The Flammability of Polyacrylonitrile and Its Copolymers I. The Flammability Assessment Using Pressed Powdered Polymer Samples

1993 ◽  
Vol 11 (5) ◽  
pp. 442-456 ◽  
Author(s):  
Jun Zhang ◽  
Michael E. Hall ◽  
A. Richard Horrocks
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Char Residue ◽  
Acrylic Polymer ◽  
Limiting Oxygen Index ◽  
Convenient Means ◽  
Burning Rates ◽  
Polymer Flammability

This paper is the first in a series of four which investigates the burning behaviour and the influence of flame retardant species on the flam mability of fibre-forming polymer and copolymers of acrylonitrile. A pressed powdered polymer sheet technique is described that enables a range of polymer compositions in the presence and absence of flame retardants to be assessed for limiting oxygen index, burning rate and char residue deter minations. The method offers a rapid, reproducible and convenient means of screening possible flame retardant systems, and LOI values compare favourably with those of films and fabrics comprising the same polymeric type. Burning rates, however, are sensitive to changes in physical sample character such as form (film vs. powder sheet) and density. Thus the technique forms an excellent basis for the generation of burning data which will enable comprehensive studies of acrylic polymer flammability and flame retardancy to be undertaken.

scholarly journals Preparation and properties of flame-retardant epoxy resins containing reactive phosphorus flame retardant

2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  
Keyword(s):  
Impact Strength ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Epoxy Resins ◽  
Phosphorus Content ◽  
Phosphorus Compound ◽  
Phosphorus Compounds ◽  
Limiting Oxygen Index ◽  
The Impact

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy.

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