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Advances in Ma terials Physics and Che mist ry, 2012, 2, 99-101 doi:10.4236/ampc.2012.24B027 Published Online December 2012 (htt p://www.SciR P.org/journal/ampc) Copyright © 2012 SciRes. AM PC Increasing the Burned Time and Mechanical Prop er t ies with New Mix As Flame Retardant Based in Hexametaphosphate of Sodium and Borax in Textile 100% Acrylic Fabrics M. Olvera-Gracia1, L. Mercado-Velazquez1, A.M. Paniagua-Mercado2 1Instituto Politécnico Nacional, ESIT – Secci ón de estud ios de Posgra do e invest igación, Av. IPN, México 2Instituto Politécnico Nacional, ESFM - Departamento de Ciencia de Materiales, México Email: manoloolvera@yahoo.com.mx Received 2012 ABSTRACT It has been worked with textil e fabrics of Acrylic 1 00% , that have as final u se the Tapestry, th is fabrics h ave been impregnat ed with a two products flame retardant: Commercial Retardant, which is formed by a combination of a resin polymeric and acid phosphoric and Borax (Na2B4O5(OH)4•8H2O) with Sodium Hexametaphosphate (Na16P14O43). These Retardants has the advantage of the fact that it can be applied to the substrates mixed with water in the relation 1:1, 1:2 or pure. In order to reduce the flammability, Textile fabrics are coated with flame retardants. The flame retardant capabilities, mechanical properties and structural characteristics of the textile fabri cs before and after th e use of these prod ucts were investigated throughout the special t extile meth ods for inflammability and mechan ical resistibil ity. Aft er the use o f the fla me retardants t he mechanical p roperties o f the fabrics were impro ved or at least remained the same as compared to fabrics without any treatment. The use of Borax / Sodium Hexametaphosphate /Water results in the essential increase of co mbustio n retardation time about 2 minutes as compared with 8 seconds for untreated fabrics. Keywords: Acrylic; Borax; Flame Retardant s ; Sodium Hexametametaphosphate; Textile Fabrics 1. Introduction Flame retardants in their various forms have been used in passive protection of timber and other building materials, including metal structures in many textiles and synthetic fibers, as well in a wide variety of technical applications of plastics, mainly in the electronics industry [1,2]. Flame retardants can be incorpo- rated into a material either as active or as additives ones. The active components are incorporated into the polymeric str uct ure of some types of plastics. This method is preferred because it produces more stable and uniform properties. Additives are also cheaper and versatile. However, they have the disadvantage to modify the properties of base materials. This is the case of the polybrominated flame retardants, which usually of view are applied as coatings or mix during the pro cessing of materials such as plasti cs and fibers [3,4]. From a technical standpoint, the effectiveness of fireproof coating is based on two fundamental aspects in depending on type of fibers. In natural fibers, as cotton and wool, it is impor- tant to maintain their properties such as of touch, comfort, etc., which do not have other heat-resistant fibers, the durability of retardan t ef fect again st washi ng, th e use an d a competi ti ve cost. In synthetic fibers, the possibility of fireproof material limits the importance of the application in the dyeing, which only has the effectiveness in blends with natural fibers, because of the strength of the effect brought by the incorporation of the addi- tive mass versus fixation by impregnation [5,6]. Regarding fireproof coating for synthetic fibers, the main interest is treatment of polyester fibers not only due to their commercial importance, either alone or in blend with other fibers, but also because of the obtained success with this fiber at flame retar- dant treatment as compared with other synthetic fibers [7]. Extreme flammability of the acrylic fibers is caused by stron g exother mic rea ction of pyrol ysis that takes p lace at temperature of 300ºC fo r most commercial varian ts. This reactio n gives rise to the formation of flammable nitriles and monoxide carbon. In order to control this reaction it is possible to add a flame retar- dant to the fiber for appreciably promotion the carbonization [8,9]. The replacement o f acrylic fibers b y firepro of modacr ylic ones is often useful, but this replacement has the disadvantage because of a very high cost of these fibers. This is the reason why there is interest of application of fireproof coating for this type of fibers to retard of flame a nd at the same time th is coat- ing must not affect the mechanical properties of fabrics im- pregnat ed. 2. Exp erimenta l Pro cedu r e Two flame retardant products based on Borax and Sodium Hexametaphosphate was used in order to coat textile fabrics with the composition 100% acrylic. Also the textile fabrics were coated with a commerci al fl ame retardan t fo r compariso n. The process of coating was carried out by the immersion me- thod, which consists of completely submerge of the fabric in a bath containing the aqueous solutions of flame retardant prod- ucts. After the coatings of the fabrics were characterized with microscopy (SEM) JEOL-6300 in order to analyze the ef fect of the flame retardant products on the fabric. The flammability tests for the samples with or without flame retardant products were carried out in order to observe their behavior under fire. M. OLVERA-GRACIA ET AL. Copyright © 2012 SciRes. AMPC 100 The tension test too was made to the samples to observe the effect of the coatings on the mechanical properties. For tensile test were used the NMX-A-059-INNTEX, whereas for ripped test a NMX-A-109-INNTEX and for inflammability test the ASTM-D6413. 3. Results and Discussion 3.1. Mechanical Properties 3.1.1. Tens ion Results After the use of the flame retardants the mechanical properties of the fabrics were improved or at least remained the same as compared with the fabrics without any treatment, because the retardants form a coated on the textiles, the better results for the tension test are those for the mix Borax/Hexametap hosphate o f Sodium/Water in the warp and weft. The results of tension test in original samples and after the treat ment with different retar dants ar e s ummarized in Table 1. 3.1.2. Ripped test Only in two values the resistance to rip is equal to the original of the acrylic warp with the commercial retardant and with the mix of Borax/Hexametaphosphate of Sodium/Water as seen in Table 2 . It is agreement with the values of elongation. The lost of elongation made the acrylic more stiffness and the sample lost resistance to rip. 3.1.3. Inflammability The flame retard ant cap abil ities of the textil e fabrics befo re and after the use of the flame retardant products were investigated using the special textile methods for inflammability. The results of the inflammability tests after the use of different products are presented in Table 3. From this table one can observe that the burning time of the fabrics treated with the solution based on Borax (Na2B4O5 OH)4•8H2O) in creased in several t imes i n d ependence on Borax concentration. The treatment with the solution Borax/H e xame- phosphate of Sodium (Na16P14O43) lead s to the same resul ts. So, Table 1 Results of the Tension Test (Kgf). Fiber Original Commercial Retardant Pure Commercial Retardant/ Water 1:1 Borax 100g/l Borax 200g/l Borax/Hex am e taphosphate of Sodium Warp 52.52 53.12 53.06 53.47 54.71 65.74 Weft 46.15 46.12 47.12 47.83 51.62 63.03 Table 2 Results of the Ripped Test (Kgf) Fiber Original Commercial Retardant Pure Commercial Retardant/ Water 1:1 Borax 100g/l Borax 200g/l Borax/Hex am e taphosphate of Sodium Warp 9.84 8.49 9.70 7.63 6.20 9.29 Weft 9.81 6.66 7.31 7.63 5.36 5.68 Table 3 Results of the In f lammability Resistance Tests (S ec.) Fiber Original Borax 100g/l Borax 200g/l Borax/Hexame taphosphate of Sodium Warp 8.62 99.71 147.93 157.85 Weft 8.53 114.07 143.27 146.88 Figure 1. SEM micrograph of the sample coated with Borax 100g/l /Hexametaphosphate of Sodium to 100g/l (1000X). these flame retardant products can stop the combustion of fa- brics on certai n di stan ce befo re the sa mple with t he co mmercial retardant product will be completely consumed. The possible explanation of such result is due to decomposition of Borax and liberation of water, which retards the fire propagation in the sample. This process takes place because of low melting point (75ºC) of Borax. For the fabrics after treatment with solution contained Borax and Hexametaphosphate of Sodium the same result s were o btained. If Borax forms water at the moment of its decomposition then the Hexametaphosphate of Sodium, which is the compound contained phosphorus and oxygen, at the de- composition gives rise phosphoric acid (H3PO4), which reacts with the hydroxyl groups released by the Borax producing of dehydration. The dehydrated materials, which were formed from the Borax, generated remaining carbon relatively fire- esistant, which functioned like a barrier and inhibited the de- gradation and protected th e material from the pyrol isis. 3.1.4. Scanning Electron Micros copy SEM was used in order to observe how the flame retardants have been deposited onto coated fibers Figure 1 it can b e seen the formation of small crystallites on the fiber surface after immersing in the solution with Borax. From this image it can be con cluded that th e covering process es of the acrylic fiber by two different retardan t materi als are dif ferent. At the sa me time Borax, also does not interact with the fiber chemical structure, however instead of the film formation crystallites grew on the fiber sur fa ce. 4. Conclusions The flammability tests the fabrics with the prep ared new flame retardant products showed very good results such as 8 seconds of combustion for the untreated fabric and 2 minutes for the fabric treated with the solution of Borax / Hexametaphosphate from Sodium /Water. This result shows the essential in crease o f combustion retardation time. The gained time space is very important as during these 2 minutes at a conflagration it is possible to save lives or to control the fire. The tension Test Resistance is better with the mix of Borax and Hexametaphos- phate than the original Acrylic. The scanning electron microscopy shows that the flame commercial r etardant is depo s ited on the su r face o f the fab r ic as M. OLVERA-GRACIA ET AL. Copyright © 2012 SciRes. AMPC 101 a thin film and the solutions based on Borax and Hexameta- phosphate of Sodium were deposited in the form of crystals on surface. These coatings do not produce any new chemical spe- cies within the internal structure of the fiber. REFERENCES [1] J. Detrell, 1998 Comportamiento al calor de los materiales textiles. Tecnitex Documentación. Terrassa, España. [2] I. Cuadra, A. Belkis, G. Infante, L. Beltrán, C. Melian, 2001 Estudio del comportamiento de la combustión de diferentes tejidos utilizados como ropas protectoras. 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