CC BY
34УДК 541.64+678.744 МРНТИ
FIRE-RETARDANT PROPERTIES OF CELLULOSE TEXTILE MATERIALS WITH THE USE OF
SOL-GEL TECHNOLOGY
Tausarova B., Baiimbetova G.
Almaty Technological University, Almaty, Kazakhstan
Abstract
The article describes research on the use of a new composition based on sodium silicate, thiourea and potassium hydrogen phosphate for imparting fire retardant properties to cellulosic textile materials. The influence of the concentration of the initial components, temperature and time of heat treatment on the fire-retardant properties of textile materials has been investigated. It is shown that cellulosic materials modified with compositions based on sodium silicate and urea, potassium hydrogen phosphate increase fire-retardant properties.
Keywords: cellulose materials, fire retardant properties, potassium hydrogen phosphate, sodium silicate, thi-ourea, sol-gel technology
Introduction
Textile materials have a wide range of applications: in everyday life, technology, public buildings, transport, are used as curtains, draperies, curtains, materials in the manufacture of upholstered furniture, sleeping accessories, special protective clothing and products, decorative finishing of various functional premises. However, they are a serious source of danger during fires, are highly flammable, contribute to the spread of flames and when gorenje emit a large amount of smoke and gases and pose a great threat to human life. Fires with high levels of smoke and toxic gas emissions are a source of serious harm to people and the environment. Toxic emissions into the atmosphere caused by large-scale fires require the evacuation of people and lead to serious environmental consequences. The problem of giving fire-resistant properties to textile materials of various nature and purpose has become increasingly relevant in recent years. In various countries, research is widely conducted to improve the fire-retardant properties of both natural and synthetic fibers. To improve the fire resistance of cellulose materials, nitrogen-phosphorus-containing compounds are treated[1-5].
The purpose of this study is to obtain cellulosic textile materials with flame retardant properties using sol-gel technology based on liquid glass, thiourea and potassium hydrophosphate.
Objects and methods of research
The solubility of liquid glass in water is due to the hydrolysis of the solution during the alkaline reaction. The pH level is 10-13, depending on the concentration of aqueous solutions. The density and viscosity of liquid glass solutions depend on the concentration of the solution, the ratio of silicic acid to temperature, and the alkalinity. Sodium liquid glass (silicate block) is diluted at a temperature of 590-670 The treated liquid glass film will be water-soluble. In a mixture with silicone gel, silicates are formed, dissolved in the chemical reaction of liquid glass with amphoteric metal chips, base metal oxides, aluminates, zincates, and seals. Under the influence of moisture and carbon dioxide in the air, the
treated film loses its properties and an alkaline-carbonate white precipitate is formed.
Liquid glass solutions are incompatible with organic substances (except sugar, alcohol, and urine), liquid dispersions of artificial resins, coagulation of organic colloidal systems, and silicate solutions. Alcohols, aldehydes, ketones, ammonia and saline solutions have a "salt" effect.
Thiourea-CS (NH2) 2 diamidiocarbon acid, thiourea, diamiotioglycolic acid, triuret, white crystals of bitter taste, melting point 180-182 ° C (with rapid heating, slow decomposition); Moderately soluble in water, methanol, pyridine, pyridine better than 50% water. Thiourea is a bright, colorless crystal. Thiourea is intended for industrial use as a raw material in the synthesis of thiol, mercaptans, dyes, synthetic resins, paraffin as a flotation agent in ore dressing processes, as a reagent for photometric determination of Bi, Os, Re, Ru. Thiourea is widely used in pharmaceuticals.
Sodium dihydrophosphate is an inorganic compound, the acid salt of the alkali metals sodium and or-thophosphoric acid with the formula NaH2 [PO] 4, forms colorless crystals, crystal hydrates, easily soluble in water.
Sodium hydrophosphate forms colorless crystals. Poorly soluble in ethanol, well soluble in water.
Glycerin (propane-1,2,3-triol) is a simple representative of triatomic alcohols with the formula CH5(OH)3. It is a viscous, transparent liquid. Glycerin is widely used in the production of paper, cosmetics and soap, as well as in the production of confectionery and alcoholic beverages. Glycerin is a colorless, viscous liquid that is not soluble in water. It has a sweet taste. Acetic acid. (ethane keto) CH_3COOH, mol. m 60.05; weak. clear liquid with a sharp smell. Without water ("ice"). Honey. 16.64 ° C, boiling point. 117.8 ° C;
Acetic acid is a colorless liquid with a sharp smell and sour taste. It is hygroscopic. It is soluble in water without restrictions.
NajSi03+2CHjC00H -4 2CHjC00Na+H2Si03 [
Research methods
Preparation of samples for practice. Preparation for the tests was carried out in accordance with the instructions of GOST 50810-95. Before carrying out the experimental work, cotton fabrics produced by JSC " Cotton Production Association named after him. Bara-novich" according to Article 1553 (1030) was washed in distilled water. The bleach was washed with water and bleached to completely remove the bath residue. After the samples were dried, a dry press was held over the dehydrated Ca [CL] _2 to determine the actual mass of the sample.
After determining the actual mass in analytical equilibrium, the cotton fabric with a size of 220x170 mm is soaked with an aqueous solution of the prepared sol.
Preparation of samples for practice. Preparation for the tests was carried out in accordance with the instructions of GOST 50810-95. Before carrying out the experimental work, cotton fabrics produced by JSC " Cotton Production Association named after him. Bara-novich" according to Article 1553 (1030) was washed in distilled water. The bleach was washed with water and bleached to completely remove the bath residue. After the samples were dried, a dry press was held over the dehydrated Ca [CL] _2 to determine the actual mass of the sample.
After determining the actual mass in analytical equilibrium, the cotton fabric with a size of 220x170 mm is soaked with an aqueous solution of the prepared sol.
Methods of research of fire-resistant properties of textile materials.
The fire resistance of textile materials mainly depends on the chemical composition of the fibers and yarn.
The fire resistance rating is carried out in accordance with the flammability and flammability (burner speed).
Tests of textile fabrics for fire resistance are carried out at a vertical, horizontal (45 °) horizontal position of simple models using heated wire.
As indicators of fire resistance of textiles are used:
- flammability - lightness or incombustibility, which characterizes the temperature and time of the sample;
gorenje gorenje-flammable substance - the rate of burning of the sample, the duration of waste incineration in seconds, the time of burning of the sample after the fire;
- duration of decomposition of the residue - time in seconds after removing the sample from the fire;
- twisting (envelope) - the height in millimeters of the darkened area as a result of thermal damage to the fibers and test fibers.
During testing, the device is placed in a special chamber with a size of 700x325x750 mm, made of a material with a thickness of 0.5-1.0 mm. The chamber arch has 32 symmetrical holes with a diameter of (13 ± 1) mm. Each of the vertical walls of the lower chamber must have symmetrically arranged ventilation openings with a total area of at least 32 cm2. One of the walls of the chamber with a size of 700x750 mm is made in the form of a closed glass door.
Test samples measuring 220x170 mm in eight directions (length) and eight directions (width). The chamber has openings for a tube that supplies gas to the heater, and handles for moving the burner. The chamber layer is made of non-flammable insulation material.
1-holder-selection frames, 2-base, 3-vertical walls, 4-heater holder, 5-heater
The composition of textile materials (natural, artificial, synthetic and fiber additives) varies depending on the production method, the structure of the fibers and yarn, as well as the density and thickness of the mesh, which affects the choice of methods and means of fire safety.
There are several ways to produce hard-to-ignite fibers and textiles:
- the use of organic polymers that are part of the high-temperature fiber;
- use of inorganic fibers;
- modification at the stage of synthesis of a fiber-forming polymer;
- modification at the stage of fiber formation using reaction and mixed type stabilizers and flame retardants;
- Surface or bulk processing of fibers, fabrics or finished products.
Where chlorine and bromine predominate among the previously used gorenje retarders, all work is currently focused on the development of halogen-free fire extinguishing systems. These halogen-containing preparations often negatively affect the polymer modification, leading to its destruction, which leads to corrosion of the device, the gorenje modifying materials is accompanied by smoke and toxic substances.
Cellulose is heated to a temperature above 250 ° C, one-third of the volatile products are water, oxide, carbon dioxide and acetaldehyde, and the rest is a resinous material with the same structure of glucosane. With prolonged heating or high temperatures, the conversion of these products can reach 90%, and also preserves the acidic product. During a fire, this glucose can burn or break down into flammable products.
In the presence of phosphates, the acid formed during their decomposition is esterified to the hydroxyl group of cellulose. The cellulose phosphate then forms a double bond, reducing the acids and reacting again. As a result, stable structures are formed in the cellulose, and in the presence of a single phosphoric acid molecule, many double bonds can be obtained.
Thus, phosphorus-containing compounds play a dual role in the protection of cellulose: first, the amount of combustible products is reduced, and secondly, the polymer is protected from the heat of a burning fire, acidic surface, as well as the resulting water. .
Based on the available literature, the evaluation and study of the fire-resistant properties of textile materials is carried out in several ways:
1) determination of flammability and flame propagation velocity
2) by determining the oxygen index
3) study of processes
4) analysis of smoke and toxic gases released by materials during gorenje
5) determination of special fire and heat protection properties.
Such a variety of test methods is due to the wide range of textile materials produced and the requirements imposed on them.
To study the fire hazard of textile materials and their application in certain areas, a large number of GOST standards and various international methods are used. For example, decorative materials, bedding, and workwear are checked according to GOST, certified, and only then can they be used for their intended purpose.
The most common way to evaluate the flame retardant properties of textiles is to determine their flammability. When the evaluation criteria are accepted: reduced fire resistance of the fabric, tensile load. The method of evaluating the refractory properties of textiles is to determine the flammability and the speed of flame propagation.
After determining the exact mass on the analytical scale, cotton fabric samples with a size of 220 x 170 mm are soaked in an aqueous solution of sodium silicate for 10-15 minutes( water: gs, 2: 1), with a CH3COOH hydrolysis catalyst (50%). 20 ml, then at the rate of 70%. The fabric was then dried at 80 ° C for 5-10 minutes.
After treatment with an aqueous solution of sodium silicate, the sample was thermally fixed at 3 different degrees of freedom, then it was impregnated with a solution of sodium dihydrophosphate and thiourea and dried at room temperature. Wash at 35 ° C, 25 ° C, then rinse with warm water at 45 ° C, and then rinse with cold water.
Table 1.
Results of the study of samples impregnated with a flame retardant
№ Concentration of substances , r/n Length of the charred area , mm Breaking load , H Breathability , gM3/ M2*C
CN O ¿75 * O £ £ CN O O T o Ph S Heat treatment temperature ,°C
100° 1200 1400 1000 1200 1400 1000 1200 1400
1 Original sample 220 220 220 190 190 190 170 170 170
2 10 6 19 121 120 100 221 220 219 160 170 137
3 10 8 29 119 130 100 220 220 219 156 169 136
4 10 10 39 120 106 98 219 219 220 155 164 139
As shown in Table 1, phosphorus samples have flame-retardant properties compared to the original fabric.
When tested for flammability in 15 seconds, the 220x170 mm raw cotton completely burned in 44 seconds. When testing phosphorus-containing samples with a size of 220x170 mm, no spontaneous ignition was observed after the combustion was stopped for 15 seconds. Gorenje In addition, the experiment was conducted with an increase in the concentration of sodium dihydrophosphate.
Fabrics, knitwear and nonwovens are subject to stretching, compression, bending, etc. when making and using clothing. feels various mechanical influences that cause deformations. The tear strength of the fabric is one of the most important indicators of its quality.
The minimum value of the tensile load, which leads to a violation of the integrity of the fabric, is
called the breaking load. The refractive load of the fabric is determined by a separate special device for the base and gap (shown in accordance with 11).
Before the resistance of the material to the tensile forces according to GOST 8847-85, the lower pressure of the PT-250M-2 was evaluated on an exhaust machine with a lowering speed.
Testing the strength of the fabric using the holder showed that the breaking load of the control sample was 220 N, and the breaking load of the cotton fabric treated with an increased content of sodium dihydrogen phosphate did not change significantly
Untreated fabric with a size of 220x170 mm, when tested for flammability at an ignition time of 15 seconds, completely burns in 60 seconds. In samples treated with a flame retardant composition, the same size of 220x170 mm at an ignition time of 15 s, the smoldering time is practically reduced to 0 at a processing temperature of 100 ° C.
Fig. 1. Electron microscopic images of cotton fabric (a) treated with a flame retardant composition concentration of K2HPO4 19 g/l (b ); 29 g/l (c); 39 g/l ( e).
A composition based on sodium silicate, thi-ochevine and potassium hydrophosphate has been developed to impart flame-retardant properties to cellulose materials.
The optimal conditions for the treatment of fabrics were determined, the effect of the concentration of the working solution, the temperature of impregnation and thermal fixation on the flame-retardant properties of the fabric was studied. The improvement of the flame-re-tardant properties of cellulose materials modified by the proposed composition is shown.
By the method of electron-scanning microscopy, it was found that the treatment of fabrics with flame-retardant compositions leads to a change in the morphology of the surface of the fibers. It is shown that cellulose materials modified with compositions based on sodium silicate, thiourea, and potassium hydrophosphate increase their flame-retardant properties. The proposed compositions ensure the achievement of higher fire resistance indicators. Processing can be carried out on the standard equipment of finishing enterprises without the stage of high-temperature fixing of the preparation.
Conclusion
1. Liquid glass, thiourea, and sodium dihydro-phosphate contributed to the formation of a new composition. The heat treatment time was studied in terms
of the concentration of the working solution, the temperature of the heat treatment, and the fire resistance of the fabric. The fire resistance of the treated samples is increased in comparison with the new undigested material based on sodium dihydrogen phosphate.
2. Using infrared spectroscopy, the interaction of measuring compositions with cellulose fibers was studied, the cotton fabric did not lose its properties even after treatment with sodium dihydrogen phosphate.
3. Initially, the surface of the untreated fabric was not smooth, and after processing, it was observed that the surface was smooth. The method of electron scanning microscopy showed that the treatment of tissues with advanced compositions leads to a change in the morphology of the surface of the fibers.
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УДК 656.135.2
DEVELOPMENT OF TECHNOLOGY OF URBAN FORWARDING SERVICE OF SMALL
CONSIGNMENT CUSTOMERS
Markevych A.,
Ph.D., Lanzhou Jiaotong University, P.R. China
Shramenko N.,
D.Sc., Professor, Kharkiv Petro Vasylenko National Technical University of Agriculture, Ukraine
Moroz M.
D.Sc., Professor, KremenchukMykhailo Ostrohradskyi National University, Ukraine
Abstract
The method of formation of rational technology of consigner's forwarding service is provided, which presumes definition of rational area of application of a certain vehicle payload and brand for operating on urban transportation routes and some practical recommendations are developed. As a criterion of efficiency, the minimum total costs for urban small consignment transportation per day were chosen. It is determined that the consignment size is subject to the normal law of distribution of a random variable while the loading and unloading time of 1 ton of consignment complies with the law of exponents. A regression analysis was performed and as well as the function of dependence of total costs for transportation of small consignments per day on the number of customers, with different values of the average consignment size and nominal vehicle payload operating on transportation routes which allows to determine the rational use of a particular brand depending on the number of customers for the corresponding value of the average consignment size.
Keywords: forwarding service, transportation routes, urban traffic, small consignment.
Relevance of work. At the present stage of development in Ukraine, more and more companies use logistics concepts such as planning deliveries "just-in-time", reducing stocks and others. This led to a decrease in the size of deliveries and an increase in the share of small consignments in the total volume of traffic. This trend is mostly observed in the transportation of goods in urban traffic.
The modern practice of small consignment transportation is characterized by small sizes of transportation to one consignee address, and the number of destinations during the day can reach from several tens to several hundreds. The problem of routing is one of the main tasks that are solved while planning small consignments transportation in urban areas, the rational solution of which largely depends on the efficiency of rolling stock and transportation costs.
For high-quality forwarding services for consignment owners in the goods transportation, it is necessary not only to deliver the specified amount of
consignment, but also to do it at a certain time, which complicates the transportation routes formation and the choice of rational vehicle payload for performing the transportation.
Given that the share of small consignments in the total volume of transportation is growing steadily, and the level of their organization is not effective enough, it is necessary to search for new scientific and practical solutions, methods and models to optimize the transportation process.
As a result of the analysis of the process of small consignments transportation organization in urban areas, a number of lacks are defined among which are the formation of irrational routes; failure to take into account customer requirements regarding the consignment delivery time; use of vehicles with irrational payload on transportation routes.
To solve routing problems for transportation, gathering and transportation and gathering routes, scientists propose to use various methods [1]. However,
