scholarly journals CONTINUOUS IMPREGNATION OF WOOD FROM THE END FACE UNDER PRESSURE WITH VARIOUS COMPOSITIONS

2021 ◽  
Author(s):  
Il'ya Medvedev ◽  
Dmitriy Parinov ◽  
Vladimir Shamaev
Keyword(s):  
Fire Resistance ◽  
Flame Retardants ◽  
Water Soluble ◽  
Uneven Distribution ◽  
Shape Stability ◽  
Entire Volume ◽  
Water Solutions ◽  
End To End ◽  
Coniferous Wood ◽  
Oak Ash

Modern impregnating compositions for wood can significantly improve its characteristics. Water-soluble and oily antiseptics, flame retardants, strengthening and plasticizing modifiers, and dyes are used as impregnating compositions. By means of impregnation, substances are introduced into the wood that increase its characteristics such as plasticity, hydrophobicity, bio- fire resistance and shape stability. But, the indicator of certain properties after impregnation of wood with a certain composition depends on the depth of impregnation, on the uniformity of the distribution of the impregnating composition over the entire volume of wood, on the concentration of the impregnating composition in the wood, on the chosen method of impregnation. It also affects which group of impregnability a particular wood belongs to, according to the breed composition, the division is made into 3 groups: 1-easily nourished rocks (birch, alder, beech, aspen sapwood, poplar, pine); 2-moderately impregnated rocks (cedar, oak, ash, maple, linden, pine core); 3-hard- to-impregnate rocks (spruce, larch, fir). Spruce and larch are considered to be almost impervious to deep impregnation of the rocks, because of their clogged pores with resin. In the autoclave method of impregnation with water solutions, the wood must be dried to a humidity of 40% before impregnation, and to a humidity of 30% when impregnated with oily liquids. After impregnation, a re-drying operation follows. Another significant disadvantage of autoclave impregnation is its uneven distribution of the absorbed liquid in the workpieces, in some workpieces too much impregnating liquid penetrates, and in others not enough. In order to avoid two dries and to be able to set the volume of liquid that the wood will absorb, as well as to ensure the uniformity of impregnation over the entire volume of wood, it is proposed to develop a technology and equipment for end-to-end impregnation of coniferous wood from the end under pressure of raw, rounded logs with a diameter of 15-35 cm and a length of 3 m.

Sorption of Water Soluble Organic Dyes on Magnetic Poly(oxy-2,6-dimethyl-1,4-phenylene)

1995 ◽  
Vol 60 (9) ◽  
pp. 1448-1456 ◽  
Author(s):  
Ivo Šafařík ◽  
Miroslava Šafaříková ◽  
Vlasta Buřičová
Keyword(s):  
Organic Compounds ◽  
Azo Dye ◽  
Organic Dyes ◽  
Water Soluble ◽  
Magnetic Composite ◽  
Water Solutions ◽  
Magnetite Particles

Magnetic composite based on poly(oxy-2,6-dimethyl-1,4-phenylene) (PODMP) was prepared by melting the polymer with ε-caprolactam in a presence of fine magnetite particles. Magnetic PODMP was used for sorption of water soluble organic compounds (dyes belonging to triphenylmethane, heteropolycyclic and azo dye groups) from water solutions. There were considerable differences in the binding of the dyes tested. In general, heteropolycyclic dyes exhibited the lowest sorption.

scholarly journals Polymer Composites Filled with Metal Derivatives: A Review of Flame Retardants

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1701
Author(s):  
R. A. Ilyas ◽  
S. M. Sapuan ◽  
M. R. M. Asyraf ◽  
D. A. Z. N. Dayana ◽  
J. J. N. Amelia ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Fire Resistance ◽  
Flame Retardants ◽  
Safety Concern ◽  
Industrial Applications ◽  
Metal Particles ◽  
Thermoplastic Composites ◽  
Flame Resistance ◽  
Metal Derivatives ◽  
Resistance Performance

Polymer composites filled with metal derivatives have been widely used in recent years, particularly as flame retardants, due to their superior characteristics, including high thermal behavior, low environmental degradation, and good fire resistance. The hybridization of metal and polymer composites produces various favorable properties, making them ideal materials for various advanced applications. The fire resistance performance of polymer composites can be enhanced by increasing the combustion capability of composite materials through the inclusion of metallic fireproof materials to protect the composites. The final properties of the metal-filled thermoplastic composites depend on several factors, including pore shape and distribution and morphology of metal particles. For example, fire safety equipment uses polyester thermoplastic and antimony sources with halogenated additives. The use of metals as additives in composites has captured the attention of researchers worldwide due to safety concern in consideration of people’s life and public properties. This review establishes the state-of-art flame resistance properties of metals/polymer composites for numerous industrial applications.

scholarly journals EFFECT OF PVA MODIFICATION ON PROPERTIES OF CEMENT COMPOSITES

2015 ◽  
Vol 55 (1) ◽  
pp. 64-75 ◽  
Author(s):  
Jaroslav Topič ◽  
Zdeněk Prošek ◽  
Kateřina Indrová ◽  
Tomáš Plachý ◽  
Václav Nežerka ◽  
...  
Keyword(s):  
Cement Paste ◽  
Building Materials ◽  
Bending Strength ◽  
Strength Reduction ◽  
Water Soluble ◽  
Cement Composites ◽  
Polymer Modification ◽  
Entire Volume ◽  
Water Soluble Polymers ◽  
Soluble Polymers

Polymers are used for modification of the cement-based composites and others building materials since the thirties of 20th century. Based on the conclusions of recent studies, it is assumed that even water soluble polymers could be used as an admixture for such modification. Currently, there exist and are exploited several possibilities for polymer modification of mortars, wood-based products or bituminous asphalts. Various options differ in the way of modification, which can be basically applied to the entire volume or just a surface, but also in the form of the polymer used – either in the form of solution or fibers. The aim of our study was to investigate the influence of volume modification by the water soluble polymers, such as polyvinyl alcohol (PVA), on the properties of cement paste and find an optimum additive. It turned out that the addition of PVA solution into fresh cement paste results in an increase of porosity and therefore a stiffness and compressive strength reduction. On the other hand, the bending strength of PVA-rich specimens was significantly higher and their water absorption decreased, which may consequently result in enhanced frost resistance.

Oxidation states of manganese porphyrins in water solutions

2005 ◽  
Vol 09 (06) ◽  
pp. 436-443 ◽  
Author(s):  
Oscar Ramirez-Gutierrez ◽  
Josep Claret ◽  
Josep M. Ribo
Keyword(s):  
Oxidation State ◽  
Water Soluble ◽  
Oxidation States ◽  
Vitreous Carbon ◽  
Alkaline Solutions ◽  
Carbon Electrode ◽  
Water Solutions ◽  
Manganese Porphyrins ◽  
Electron Reduction ◽  
Mn Porphyrins

The Mn oxidation state of two water soluble Mn porphyrins, MnTMPyP and MnTPPS 4, was studied as a function of the aqua or hydroxo ligands of the Mn atom. In NaOH solutions, long-lived O = Mn(IV) species were detected in the presence of O 2. Conversely, the dihydroxo Mn(III) porphyrin reduces spontaneously to the Mn(II) species in the absence of O 2. In alkaline solutions, these Mn porphyrins were able to electrocatalyze the 4-electron reduction of O 2 to H 2 O on a vitreous carbon electrode.

scholarly journals Effect of Poly(acrylamide-acrylic acid) on the Fire Resistance and Anti-Aging Properties of Transparent Flame-Retardant Hydrogel Applied in Fireproof Glass

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3668
Author(s):  
Feiyue Wang ◽  
Mengtao Cai ◽  
Long Yan
Keyword(s):  
Acrylic Acid ◽  
Flame Retardant ◽  
Fire Resistance ◽  
Flame Retardants ◽  
Heat Insulation ◽  
Accelerated Aging ◽  
Light Transmittance ◽  
Mass Ratio ◽  
Aging Properties ◽  
Poly Acrylamide

Poly(acrylamide-acrylic acid) (P(AM-co-AA)) was synthesized via the copolymerization of acrylamide and acrylic acid and well characterized by Fourier transform infrared spectroscopy. Afterward, the obtained P(AM-co-AA) was blended with flame retardants to prepare transparent flame-retardant hydrogel applied in the fireproof glass. The influence of poly(acrylamide-acrylic acid) on fire resistance and anti-aging properties of the transparent flame-retardant hydrogels were studied by assorted analysis methods. The optical transparency analysis shows that the light transmittance of the transparent flame-retardant hydrogel gradually decreases with the decreasing mass ratio of acrylamide to acrylic acid in P(AM-co-AA). Heat insulation testing shows that the heat insulation performance of fireproof glass applying the transparent flame-retardant hydrogel firstly decreases and then increases with decreasing mass ratio of acrylamide to acrylic acid in P(AM-co-AA). When the mass ratio of acrylamide to acrylic acid is 1:2, the obtained P(AM-co-AA) endows the resulting flame-retardant hydrogel applied in fireproof glass with the lowest light transmittance of 81.3% and lowest backside temperature of 131.4 °C at 60 min among the samples, which is attributed to the formation of a more dense and expanded char to prevent the heat transfer during combustion, as supported by the digital photos of char residues. The results of TG analysis indicate that P(AM-co-AA) imparts high thermal stability to the resulting hydrogels due to the hydrogen bonds between carboxyl and amide groups. The accelerated aging test shows that the transparent flame-retardant hydrogel containing P(AM-co-AA) is less affected by aging conditions. Especially, when the mass ratio of acrylamide to acrylic acid in P(AM-co-AA) is 4:1, the resulting transparent flame-retardant hydrogel shows a light transmittance of 82.9% and backside temperature of 173.1 °C at 60 min after 7 aging cycles, exhibiting the best comprehensive properties among the samples.

scholarly journals Effects of Aluminum Hydroxide and Layered Double Hydroxide on Asphalt Fire Resistance

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1939 ◽  
Author(s):  
Menglin Li ◽  
Ling Pang ◽  
Meizhu Chen ◽  
Jun Xie ◽  
Quantao Liu
Keyword(s):  
Carbon Monoxide ◽  
Layered Double Hydroxide ◽  
Aluminum Hydroxide ◽  
Fire Resistance ◽  
Flame Retardants ◽  
Synergistic Effects ◽  
Combined System ◽  
Limiting Oxygen Index ◽  
Double Hydroxide ◽  
The Impact

When a fire occurs in a tunnel, the instantaneous high temperature and smoke cause great danger to people. Therefore, the asphalt pavement material in the tunnel must have sufficient fire resistance. In this study, the effects of aluminum hydroxide and layered double hydroxide on the fire resistance of styrene-butadiene-styrene (SBS) polymer-modified asphalt was investigated. The fire resistance of the asphalt was evaluated by using a limiting oxygen index (LOI). The impact of aluminum hydroxide (ATH), layered double hydroxide (LDHs), and mixed flame retardant (MFR) on LOI was studied. The synergistic fire resistance mechanism of ATH and LDHs in asphalt binder was analyzed by using an integrated thermal analyzer‒mass spectrometry combined system (TG-DSC-MS) and Fourier transform infrared spectrometer (FTIR). The experimental results indicated that the main active temperature range of these flame retardants was 221–483 °C. The main components of smoke were methane, hydroxyl, water, carbon monoxide, aldehyde, carbon dioxide, etc. The addition of flame retardants could inhibit the production of methane, carbon monoxide, and aldehyde. Moreover, due to the good synergistic effects of ATH and LDHs, 20 wt % MFR had the best fire resistance.

scholarly journals Preparation and Absorption Carbon Monoxide Properties of a Novel Flame Retardants Based Fire-Fighting Foam

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiujuan Li ◽  
Ruisong Guo ◽  
Xiaodong Qian
Keyword(s):  
Carbon Monoxide ◽  
Flame Retardant ◽  
Magnesium Hydroxide ◽  
Flue Gas ◽  
Flame Retardants ◽  
Water Soluble ◽  
Gas Temperature ◽  
Fire Extinguishing ◽  
Film Forming ◽  
Co Concentration

The toxicity of CO threatens the life of people in the fire site. In this study, flame retardants of nano magnesium hydroxide particles and water-soluble flame retardant 8124 are used to be mixed into the aqueous film forming fire extinguishing agent (AFFF). Smoke-suppressed fire extinguishing agent was prepared in Waring-Blender mixing cup and then stirred at 3,000 r/min for 5 min. The new extinguishing agent shows a good performance of absorption of CO and reducing the flue gas temperature. The concentration of CO was decreased below 131 ppm and flue gas temperature was basically kept below 40°C, which was 367 ppm and 83.1°C less than that in free-fire. Using new extinguishing agent can effectively reduce the harm to the trapped personnel and firemen in the fire site. It was of great significance. The harm of CO concentration below 131 ppm and flue gas temperature below 40°C was low. The time to reach the maximum CO concentration and the maximum flue gas temperature was delayed, which ensures that people have more time to escape. Even if there was not enough time to escape, people will not be seriously threatened.

scholarly journals Synergistic Effect of Mica, Glass Frit and Melamine Cyanurate for Improving Fire Resistance of Styrene-Butadiene Rubber Composites Destined for Ceramizable Coatings

2018 ◽  
Author(s):  
Mateusz Imiela ◽  
Rafał Anyszka ◽  
Dariusz Bieliński ◽  
Magdalena Lipińska ◽  
Przemysław Rybiński ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Flame Retardant ◽  
Fire Resistance ◽  
Flame Retardants ◽  
Glass Frit ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Melamine Cyanurate ◽  
Before And After ◽  
Styrene Butadiene

Synergistic effect of different fillers is widely utilized in polymer technology. The combination of various types of fillers is used to improve various properties of polymer composites. In this paper a synergistic effect of flame retardants was tested for the improvement of ceramizable composites performance. The composites were based of styrene-butadiene rubber (SBR) used as polymer matrix. Three different types of flame retardants were tested for synergistic effect: Mica (phlogopite) high aspect-ratio platelets along with low softening point temperature glass frit (featuring ceramization effect) and melamine cyanurate, a commonly used flame retardant promoting carbonaceous char. In order to characterize the properties of the composites, combustibility, viscoelastic properties and mechanical properties before and after ceramization were tested. The results obtained show that the synergistic effect of ceramization promoting fillers and melamine cyanurate is especially visible with respect to the flame retardant properties resulting in a significant improvement of fire resistance of the composites.

scholarly journals Effect of UV light on food quality and safety

2019 ◽  
Vol 12 (1) ◽  
pp. 21-41
Author(s):  
J. Csapó ◽  
J. Prokisch ◽  
Cs. Albert ◽  
P. Sipos
Keyword(s):  
Uv Light ◽  
Photochemical Reactions ◽  
Water Soluble ◽  
Quality And Safety ◽  
Uv Treatment ◽  
Entire Volume ◽  
Dna And Rna ◽  
Food Quality And Safety ◽  
Pyrimidine Bases ◽  
Odorous Substances

Abstract The recent years have seen a great number of instances when ultraviolet (UV) radiation was used in the preservation process of all sorts of foods. Since the purine and pyrimidine bases of DNA and RNA absorb well the 254 nm radiation, its application with the use of a correct dosage can result in disinfections of various orders of magnitude. It can be particularly effective in cases where technology does not allow a more intensive heat treatment. When used properly, UV treatment can be a competitive procedure in the case of foodstuffs where the large surface area allows for UV rays to penetrate the entire volume of the substance. Incorrectly applied UV treatment may change the composition of foods. Free-radical as well as photochemical reactions can digest the proteins, damage the antioxidants, oxidize the lipids, make changes to the colour and substance, and produce undesirable flavourings and odorous substances. Some vitamins are particularly sensitive to UV irradiation in the course of which losses could reach even 50%. Photosensitive water-soluble vitamins are vitamin C, B12, B6, B2 and folic acid, while vitamins A, K and E are the fat soluble sensitive to light, carotene being the only provitamin with such properties. On the other hand, UV treatment can be a useful tool of food safety because of the photosensitivity of fungal toxins.

The effect of fire protection means on the intensity of heating and features of charring of wooden structures

2021 ◽  
Vol 94 ◽  
pp. 50-64
Author(s):  
I. O. Fedotov ◽  
◽  
A. B. Sivenkov ◽  
Keyword(s):  
Flame Retardant ◽  
Fire Resistance ◽  
Fire Protection ◽  
Flame Retardants ◽  
Large Scale ◽  
Fire Hazard ◽  
Experimental Studies ◽  
Systematic Research ◽  
Muffle Furnace ◽  
Wooden Structures

Introduction. Over the past decades, the sphere of wooden house construction has been undergoing revolutionary changes in relation to the development of large-scale construction using wood-based structures. In this regard, one of the first places is the direction associated with ensuring the fire-safe use of such structures in the construction of buildings and structures of various functional purposes. An important sector of this direction is various types and methods of fire protection for wood, materials and structures based on it. The lack of systematic research on these issues hinders the development of effective technical solutions for fire protection of wooden structures. Goals and objectives. Identification of priority areas for research in the field of fire protection of wood, materials and structures based on it. Development of effective flame retardants that can have an impact on reducing fire danger and increasing the fire resistance of wooden structures. Determination of the influence of various flame retardants on the intensity of the process of heating and charring of elements of wooden structures in conditions of fire exposure (fire). Methods. A standard muffle furnace of the SNOL type was used as a test installation with the possibility of one-sided radiation thermal effect on the sample surface and a uniform temperature increase in the furnace up to 1200 С. The muffle furnace was upgraded taking into account the horizontal fixing of the sample on the outer panel of the furnace. To measure the temperature by the thickness of the sample, a set of thermoelectric converters of type K (chromel-kopel) with a junction diameter of 0,8 mm was used. Results and their discussion. Based on the results of theoretical and experimental studies, the main directions of research on the possibility of using various methods and types of fire protection to achieve the required fire hazard characteristics and fire resistance of wooden structures were determined. During the study, the analysis of such characteristics of charring as the rate of charring, the thickness of the charred layer was carried out. Conclusion. The research results show the possibility of certain classes of flame retardants, intumescent and heat-protective materials not only to influence the intensity of the process of charring wood, but also to affect the properties and structure of the charred layer, as well as the intensity of heating of the inner layers of wooden structures. Key words: fire resistance, fire resistance limit, fire hazard, charring, heating intensity, flame retardant efficiency, wood, wooden structures, flame retardant coatings, flame retardants.

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