1,721,007 research outputs found
Thermal behaviour and flame retardancy of monoethanolamine-doped sol-gel coatings of cotton fabric
Get PDFRecent studies have shown that the combustion behaviour of cellulose-based materials can be strongly affected by the presence of a protective phosphorus-rich silica coating obtained with a promising sol-gel approach. Thus, in the present work, monoethanolamine (MEA) was used in combination with diethylphosphatoethyltriethoxysilane sol-gel precursor (DPTES) to investigate both the ability of MEA to neutralize the acidic conditions of DPTES sol before cotton fabric treatment and the fire resistant properties of the obtained coating (COT-A). Moreover, to study the influence of an inorganic–organic silica matrix on the durability of the proposed flame retardant finishing, the DPTES-MEA sol was mixed with tetraethoxysilane (TEOS) and 3-glycidoxypropyltriethoxysilane (GPTES) precursors, to produce hybrid coatings on cotton fibres (COT-B). Scanning Electron Microscope (SEM) and Attenuated Total Reflection-Infrared (ATR-IR) spectroscopy were used to characterize the surface morphology, as well as the chemical structure of the treated and untreated fabrics. Furthermore, thermogravimetric Analysis (TGA), Microscale Combustion Calorimeter (MCC), and Limiting Oxygen Index (LOI) were performed on the treated cotton fabrics with a promising outcome. The results showed that DPTES-MEA sol is able to enhance the thermal and thermo-oxidative stability of cotton, exploiting the joint effect of thermal shielding (exerted by the silica phases) and char-forming (exerted both by the phosphoric acid source present in the alkoxysilane precursor and by the nitrogen content in MEA). Both proposed sol-gel treatments allow the cotton samples to achieve a LOI value of 29, classifying them as self-extinguishing materials
New halogen-free and environmentally-friendly flame retardant finishing for polyester fabrics
No full textIn this study, a bifunctional 3-glycidoxypropyltrimethoxysilane (GPTMS) precursor, containing methoxysilyl groups and an epoxy group, has been used to synthesize a hybrid organic-inorganic coating for textile finishing. It has been chosen because it combines excellent properties like the possibility to immobilize specific molecules (through the reactive epoxy group) and the binding capacity with the textile surface (through the hydrolyzed Si-OH groups). This immobilization technique has been studied previously [1, 2] and here it has been employed in order to prepare thin films in the presence of Boehmite nanoparticles (AlOOH). The thermal properties and flame retardancy of the so-treated polyester fabrics (PET) have been assessed by using thermo gravimetric analysis and vertical flame spread test, respectively. In addition, the morphology and surface composition of untreated and treated samples have been evaluated by Scanning Electron Microscopy (SEM) coupled with elemental analyses by EDX (Energy Dispersive X-ray)
Multifunctional silica sol-gel finishing for textile fabrics
No full textIn this research the way of producing functional textile finishings by the sol-gel process is discussed. The multistep approach, consisting of consecutive depositions of sol layers on cotton fabric, is used to obtain architectures with a different number of layers. To this aim, tetraethoxysilane (TEOS) has been used as a precursor and the role of such architectures has been deeply investigated and correlated with the sol concentration and with the presence of Dibutyltindiacetate, as condensation catalyst. The results obtained should be interpreted according to the properties investigated. The higher the concentration and the number of layers of the inorganic matrix, the higher the heat protection of textile samples. To improve the mechanical properties the best results were obtained by modulating a lower concentration of the matrix using a layered approach
Synthesis and characterization of hybrid phosphorus-silica films for halogen-free flame retardant cotton fabrics
No full textDiethylphosphatoethyltriethoxysilane has been used as a functional alkoxysilane in consecutive sol-gel depositions on cotton fabrics, for obtaining architectures with a different number of layers (namely, 1, 3 or 6 layers). The role of such architectures has been deeply investigated and correlated with the final properties of the treated fabrics. Afterwards, 3-aminopropyltriethoxysilane and N,N,N',N',N'',N''-hexakis methoxymethyl-[1,3,5]triazine-2,4,6-triamine have been reacted with diethylphosphatoethyltriethoxysilane to investigate the effect of the concurrent presence of Si, P and N on the flame retardancy properties of the cellulosic fabrics. Finally, the synergistic or additive effects due to the concurrent presence of phosphorus and nitrogen-based compounds have been thoroughly investigated. Flammability and cone calorimetry tests have shown that only phosphorus (i.e. bisphosphonate) is able to promote a certain synergism with the sol-gel derived oxide phases in terms of residue, heat release rate and total burning time
Tauc plot characterization and optical properties of titania thin films on cotton fabrics
No full textIn recent years, TiO2 has been widely studied for its potential perfomances in many scientific and technological fields. TiO2 is also used as textile-finishing agent to impart several properties such us self-cleaning, UV-absorption, etc. In this study, optical properties and Tauc plot characterization have been performed to assess the features of the titania films on the textile fabrics. Moreover, the photocatalytic activity of the treated samples has been evaluated monitoring the photobleaching of a dye
Phosphorus-Silica Sol-Gel Hybrid Coatings for Flame Retardant Cotton Fabrics
No full textThis work investigates the use of organic-inorganic sol-gel coatings based on silica and phosphorous com- pounds for providing cotton fabrics with flame retardant features. To this aim, diethylphosphatoethyltri- ethoxysilane precursor was employed for the synthesis of several sols in combination with different chem- ical additives. Sols were reacted with azo-based compounds and repeatedly applied onto the cellulosic substrate in a multilayer assembly, aiming at assessing the effect of the concurrent presence of Si, P and N on the overall fire behaviour of the fabric. In order to evaluate the flame retardancy of treated cellulosic fab- rics, flammability tests were carried out. The obtained results showed that the phosphorus-silica coating is able to promote the formation of a stable char that acts as insulator barrier. Finally, an additive P-N effect of the ceramic oxide coating in terms of increased residue and decreased heat release rate and total burning time was observed in cone calorimetry tests
Halogen free phosphorus-based hybrid silica coatings for conferring flame retardancy to cellulosic fabrics
No full textThe present study involves the use of hybrid sol-gel coatings based on silica and phosphorous compounds to develop flame retarded cotton fabrics. To this aim, diethylphosphatoethyltriethoxysilane (DPTS) precursor has been used for the synthesis of several sols in combination with different chemical additives. The DPTS sols were reacted with azo-based compounds to investigate the effect of the concurrent presence of Si, P and N and applied in consecutive depositions on textile samples. Flammability tests were performed to evaluate the flame retardancy of treated cellulosic fabrics. The obtained results have shown that phosphorus-silica network is able to promote the formation of char that acts as insulator barrier. An additive P-N effect of the ceramic oxide matrix in terms of increased residue and decreased heat release rate and total burning time has been observed
Flame retardant finishings by sol-gel technique
No full textThis paper describes the use of sol-gel treatments for conferring flame retardant features to cotton. To this aim, a phosphorus-containing alkoxysilane (namely, diethylphosphatoethyltriethoxysilane) has been applied in consecutive depositions on textile samples. Furthermore, azo-based compounds have been reacted with diethylphosphatoethyltriethoxysilane to investigate the effect of the concurrent presence of Si, P and N on the flame retardancy of the cellulosic fabrics, assessed through flammability and cone calorimetry tests. The obtained results have shown that phosphorus is able to promote an additive effect with the sol-gel derived oxide phases in terms of increased residue and decreased heat release rate and total burning time
- …
