Having collected a significant collection of dark color hyphomycetes allocated from different habitats, we began to study the attitude of natural isolates of mushrooms to UV radiation. Such a study made it possible to identify differences in UV sustainability among the widespread species and childbirth of the dematiaceae family, determine the distribution of this feature within each biocenosis, its taxonomic and environmental significance.

We have studied resistance to UV rays (254 nm, dose intensity of 3.2 J / m 2) 291 cultures of mushrooms isolated from meadow and flood-meadow (21 types of 11 types of birth), high-altitude (25 species of 18 types) and saline (30 species 19 genera) soil. When studying the UV-stability of DEMATICEAE cultures isolated from the plain salted soils of the South of the Ukrainian SSR, proceeded from the assumption that with the rise of adverse conditions of existence due to the soil salinity in it will be accumulated greater than in other soils the number of sustainable types of dark color hypomycetes. In some cases it turned out to be impossible to determine the UV resistance due to the loss or sporadicity of the spiones in the species.

We studied natural isolates of dark color hypomycetes, in connection with this, each sample was characterized by an unequal number of cultures. For some rare species, the sampling amount did not allow to carry out appropriate statistical processing.

The widespread and frequently found genus cladosporium is represented by the largest number of strains (131), unlike Diplorhinotrichum, Haplographium, Phialophora, and others, allocated only in isolated cases.

The studied mushrooms were conditionally divided into highly resistant, stable, sensitive and highly sensitive. Such a highly resistant and stable attributed such, the survival rate of which after the 2-hour exposure of UV rays was more than 10% and from 1 to 10%, respectively. Types, the survival rate of which ranged from 0.01 to 1% and from 0.01% and lower, we were attributed to sensitive and highly sensitive.

Large fluctuations in the UV stability of studied dark color hyphomycetes are revealed - from 40% and more than 0.001%, i.e. within five orders of magnitude. These fluctuations are somewhat smaller at the level of birth (2-3 orders) and species (1-2 of the procedure), which is consistent with the results obtained, on bacteria and cultures of plant tissues and animals (Samoilova, 1967; Tin, 1968).

Of the 54 species studied family Dematiaceae highly resistant to prolonged UV radiation 254 nm Helminthosporium turcicum, Hormiscium stilbosporum, Curvularia tetramera, C. lunata, Dendryphium macrosporioides, Heterosporium sp., Alternaria tenuis, a significant portion of strains Stemphylium sarciniforme. All of them differ intensively pigmented, rigid cell walls and, with the exception of Dendryphium Macrosporioides, HeteroSPORIUM Sp. And Hormiscium Stilbosporum belongs to the Didimosporae and Phragmosporae groups of the Dematiaceae family characterized by large multicellular conidias.

A much larger number of types are resistant to UV rays. These include species of childbirth Alternaria, Stemphylium, Curvularia, Helminthosporium, Bispora, Dendryphion, Rhinocladium, Chrysosporium, Trichocladium, Stachybotrys, Humicola. The distinctive features of this group, as well as the previous one, are large conides with rigid, intense pigmented walls. Among them, the Mushrooms of Didimosporae and Phragmosporae, Alternaria, Helminthosporium, Dendryphion, were also significant among them.

By UV-sensitive allocated 23 species mafic filamentous fungi:... Oidiodendron, Scolecobasidium, Cladosporium, Trichosporium, Haplographium, Periconia, Humicola fusco-atra, Scytalidium sp, Alternaria dianthicola, Monodyctis sp, Peyronella sp, Curvularia pallescnes etc. Attention is drawn to. Attention that species A. Dianthicola and C. Pallescens, condidium of which are less pigmented, are sensitive to UV rays, although the remaining types of these clans are stable and even highly resistant.

According to the adopted division, the types of widespread and presented in our studies are the highest number of cladosporium stem strains: S. Linicola, S. Hordei, S. Macrocarpum, S. Atroseptum. S. Brevi-Compactum var. Tabacinum) and highly sensitive (with . Elegantulum, S. Transcheliai, S. Transcheliai Var. Semenicola, S. GRISEO-Olivaceum).

Types of cladosporium clauses belonging to the first group differed sufficiently dense, intensely pigmented, rough cellular shells, in contrast to the second type of species whose cell walls are thinner and less pigmented. Sensitive types, the survival of which, after irradiation with a dose of 408 J / m 2, was less than 0.01%, - DiplorHinotrichum Sp., Phialophora Sp., Chloridium Apiculatum and others. Large-colored gifomycetes in this group were absent. Highly sensitive to UV irradiation, species had small, weakly pigmented or almost colorless condes.

Some species of dematiaceae studied the morphology of conidium formed after irradiation with a dose of 800 J / m 2. Condidia Cladosporium Transcheliai, S. Hordei, S. Elegantulum and S. Brevi-Compactum formed after irradiation, as a rule, larger than that of unwound species. Especially clear this tendency was manifested in basal conidias. Noticeable changes in the morphology of conidium were also observed among the Curvularia Geniculata, Alternaria Alternata, Trichocladium Opacum, Helminthosporium Turcicum, they were found only after irradiation with large doses of UV rays of about 10 3 J / m 2. At the same time, Curvularia Geniculata conjudis was noticeably led and became almost direct, in the conidias of Alternaria Alternata, the number of longitudinal partitions was reduced to a complete disappearance, and they themselves became larger than the controls. On the contrary, Konidiya N. Turcicum became smaller, the number of partitions in them decreased, sometimes partitions became curved. In the conidias of Trichocladium Opacum, there was an emergence of individual, unusually swollen cells. Such changes in morphology indicate significant violations of the processes of growth and division in irradiated mushrooms.

The study of natural isolates of the Mushrooms of the dematiaceae family confirmed a certain dependence of UV resistance from the magnitude of the conidium and pigmentation of their shells. As a rule, large conides are more stable than small. It should be noted that the indicator selected is the survival rate - melanin-containing mushrooms after irradiation with a dose of 408 J / m 2 indicates a high stability of a group of mushrooms in general, superior to such a unique micrococcus RADIODUANS microorcccus microorganisms (Moseley, Copland, 1975) and Micrococcus Radiophilus (Lewis , Kumita, 1972). It is clear that the nature of such a phenomena needs further study with the involvement of highly resistant and sustainable species of the species of the DEMATICEAE family.

We studied the distribution of the feature of UV resistance in dark color mushrooms isolated from flood-meadow, saline and high-mountain soils, which were depicted graphically. The curves obtained resembled the curves of the normal distribution (Lakin, 1973). The survival rate of most (41.1 and 45.8%) crops isolated from meadow and saline soils of Ukraine, after a dose of 408 J / m 2 (2-hour exposition) 0.02-0.19%, and resistance to this The factor was distributed within 6 orders. Consequently, the assumption of increased resistance to UV irradiation of dark color hyphomycetes from saline soils was not confirmed.

It was noticeably different from the high-altitude species of the DematiaceaE family described above, which was reflected in the change in the position of the peak curve and the scope of the distribution.

For 34.4% of crops, survival accounted for 0.2-1.9%. The survival rate of 39.7% of the isolates exceeded 2%, i.e. the distribution curve of the SF-stability is shifted in the direction of increased resistance to UV irradiation. The scope of the distribution on this property did not exceed four orders.

Due to the distinguished differences in the distribution of the feature of UV-resistance among the equifined and high-altitude species and genera of the Dematiaceae family, it was advisable to check due to which they occur: due to the predominant occurrence of highly resistant and resistant to UV rays of trees of dark color hypomycetes in mountain soils or there is an increased Resistance to UV radiation of high-altitude strains of the same type or kind compared to the plains. To prove the latter, there was a comparison of the cultures of the dematiaceae family isolated on the surface of the plain and alpine soils, as well as from surface (0-2 cm) and deep (30-35 cm) of the horizons of the plain meadow soils. Obviously, such mushrooms are in extremely unequal conditions. The samples we used were allowed to analyze in the sign of the UV-stability of 5 common genera of the dematiaceae family isolated on the surface of the plain and alpine soils. Only strains isolated from high-mountain soils, species of cladosporium and Alternaria species are reliably more resistant than strains isolated from equible soils. UV stability of strains isolated from equible soils, on the contrary, was significantly higher than the highly mountainous. Consequently, the differences in relation to UV rays in mycoflorians with increased insolation (high-mountain soils) are determined not only by the preferential occurrence of sustainable childbirth and types of dematiaceae, but also possibly adapting them to such conditions. The last position obviously has a private value.

Comparison of the UV-stability of the cultures of the most common genera of dark color hyphomycetes isolated from surface, exposed to light, and deep soil horizons, showed the absence of statistically reliable differences between them. The range of changes in the sustainability of UV rays in natural isolates of widespread types of dematiaceae was mostly the same in equible and high-altitude isolates and did not exceed two orders. Wide variability on this feature at the level level ensures the possibility of surviving a sustainable part of the species population in environmentally unfavorable conditions for this factor.

The conducted studies confirmed the extremely high UV-stability of Schmphylium Ilicis, S. Sarciniforme, Dicoccum Asperum, Humicola Grisea, Curvularia Geniculata, Helminthosporium Bondarzewi, which, after a dose of irradiation, about 1.2-1.5 ∙ 10 3 J / m 2 to 8-50% of the conidium remained alive.

The next task was to study the sustainability of certain types of the dematiaceae family to biologically extreme doses of UV radiation and the artificial sunlight (ECH) high intensity (Zhdanov et al. 1978, 1981).

They irradiated the monolayer dry conidium on the gelatin substrate according to the method of Lee, modified by us (Zhdanov, Vasilevskaya, 1981), and received comparable, statistically reliable results. The source of UV radiation served as a lamp DRS - 1000 Co Filter Fox-1, transmitting UV rays 200-400 nm. The intensity of the light flux was 200 J / m 2 ∙ s. It turned out that Stemphylium Ilicis, CladoSporium Transcheliai and especially his mutant S-1 is highly resistant to this impact.

So, survival rate S. Ilicis after a dose of 1 ∙ 10 5 J / m 2 was 5%. 5% survival rate for mutant H-1, C. transchelii, mutants K-1 and BM was observed after doses 7.0 ∙ 10 4; 2.6 ∙ 10 4; 1.3 ∙ 10 4 and 220 J / m 2, respectively. The graphically the death of irradiated dark-painted conidium was described by a complex exponential curve with an extensive plateau, in contrast to the survival of a mutant BM, which obeyed exponential addiction.

In addition, we have experienced stability of melanin-containing mushrooms to high intensity. The radiation source was the illuminator solar (OS - 78) based on the DSR-3000 xenon lamp, which provides radiation in the wavelength range of 200-2500 nm with the spectral distribution of energy close to the sunny. In this case, the proportion of energy in the UV region was 10-12% of the total radiation stream. The irradiation was carried out in the air or under vacuum conditions (106.4 MK PA). The intensity of radiation in the air was 700 J / m 2 ∙ C and in vacuo - 1400 J / m 2 ∙ C (0.5 and 1 solar dose, respectively). One solar dose (solar constant) is the magnitude of the total stream of solar radiation outside the earth's atmosphere at the average distance of the earth - the sun falling on 1 cm 2 of the surface in 1 s. Measuring the specific exposure was made according to a special procedure on the position of the sample using a Luximeter 10-16 with an additional neutral light filter. Each strain was irradiated at least 8-15 consecutive increasing doses of radiation. The irradiation time varied from 1 min to 12 days. The sustainability of the ISS was judged by the survival of conidia mushrooms (the number of macrocolonium formed) relative to the uncompressed control, adopted for 100%. In total, 14 species of 12 genera are the dematiaceae family, of which 5 species have been studied in more detail.

The stability of the cultures of S. Transcheliai and his mutants to the ISS depended on the degree of their pigmentation. Graphically, it was described by a complex exponential curve with an extensive resistance plateau. The value of LD 99.99 when irradiated in the air for a mutant P-1 was 5.5 ∙ 10 7 J / m 2, the source culture of C. transchelii - 1.5 ∙ 10 7 J / m 2, light-colored mutants K-1 and BM - 7.5 ∙ 10 6 and 8.4 ∙ 10 5 J / m 2, respectively. The irradiation of the Mutant P-1 under vacuum conditions turned out to be more favorable: the stability of the mushroom increased noticeably (LD 99.99 - 2.4 ∙ 10 8 J / m 2), the type of dosic survival curve (multicomponent curve) has changed. For other strains, such irradiation was more destructive.

When comparing stability to UV-rays and the HIGH-intensity of Cultures S. Transcheliai and his mutants, a lot of general is established, despite the fact that the impact of the ISS was studied on the "dry" conidias, and the UV rays were irradiated with a water suspension. In both cases, the direct dependence of the sustainability of fungi from the content of melanin pigment PC in the cellular shell is found. Comparison of these properties indicates the participation of pigment in the sustainability of mushrooms to the ISS. The mechanism of photographic effect of melanin pigment proposed in the future makes it possible to explain the lengthy stability of melanin-containing mushrooms to total doses of UV rays and ISS.

The next stage of our work was to find more resistant to this factor of the cultures of melanin-containing mushrooms. They were the types of stemphylium, and the stability of the cultures S. Ilicis and S. Sarciniforme in the air is about the same, extremely high and is described by multicomponent curves. The maximum radiation dose 3.3 ∙ 10 8 J / m 2 for said cultures corresponded to LD 99. In vacuo, with more intensive irradiation, the survival rate of the cultures of the stemphylium ilicis was somewhat larger than S. Sarciniforme (LD 99 is 8.6 ∙ 10 8 and 5.2 ∙ 10 8 J / m 2, respectively), i.e. survival Almost the same and also described by multicomponent curves with an extensive plateau at the level of survival rate of 10 and 5%.

Thus, the unique stability of a number of representatives of the Dematiaceae family (S. Ilicis, S. Sarciniforme, a mutant C. transchelii h-1) was found to the long-term exposure to high intensity. In order to compare the results obtained with previously known, we decreased by the value of sublutal doses obtained for our objects, since the UV rays (200-400 nm) of the OS-78 installation was 10% in its light stream. Consequently, the survival rate of about 10 6 -10 7 J / m 2 in our experiments by 2-3 times exceeds such, known for high-resistant microorganisms (Hall, 1975).

In the light of the ideas about the mechanism of the photographic action of melanin pigment (Zhdanov et al., 1978), the interaction of the pigment with fusion quanta led to photocosis of it in a mushroom cell and in the future to stabilize the process by reversible electron photoconduration. In the atmosphere of Argon and in Vacuum (13.3 m / P), the character of the photochemical reaction of the melanin pigment remained the same, but photocosis was expressed weaker. The increase in the UV-stability of the conidium of dark color hyphomycetes in vacuum can not be associated with an oxygen effect, which is absent when the "dry" samples are irradiated. Apparently, in our case, the conditions of the Vacuum contributed to a decrease in the level of photocosis of the melanin pigment responsible for the rapid death of the cell population in the first minutes of irradiation.

Thus, the study of the resistance to UV radiation about 300 cultures of the representatives of the dematiaceae family showed significant UV resistance to this effects of melanin-containing mushrooms. Within the family, the inhomogeneity of species on this feature is established. UV stability presumably depends on the thickness and compactness of the location of melanin granules in the mushroom cell shell. The stability of a number of dark color species to the sources of UV rays of high power (DRS-1000 and DKSR-3000 lamps) was tested and an extremely stable group of species was detected, which is significantly superior to such types of microorganisms such as Micrococcus Radiodurans and M. Radiophilus. The peculiar nature of the survival of dark color hyphomycetes by type of two and multicomponent curves, which are first described by us.

A study of the distribution of a sign of sustainability to UV-rays of dark color hypomycetes in high-mountain soils of the Pamir and Pamiro-Alya and in the meadow soils of Ukraine has been carried out. In both cases, it resembles a normal distribution, but in the Mikoflorian alpine soils clearly prevailed UV-sustainable types of family Dematiaceae. This suggests that solar insolation causes deep changes in the Mikoflorian surface horizons of the soil.

Enamel resistance to fading

The conventional light resistance was determined on the samples of the RAL 7016 dark gray enamels on the PVC profile of Rehau Blitz.

The conditional light resistance of the paintwork was determined in tests in accordance with the standards:

GOST 30973-2002 "Polyvinyl chloride profiles for window and door blocks. Method for determining the resistance to climatic influences and evaluation of durability." Section 7.2, Table.1, approx. 3.

The determination of the conditional light resistance with the radiation intensity of 80 ± 5 W / m 2 was monitored by changing the gloss of coatings and color characteristics. The color characteristics of the coatings were determined on the "Spectroton" device after the samples are wiping with dry winds to remove the resulting plaque.

The change in the color of the samples during the test was tried to change the color coordinates in the CIE LAB system, calculating ΔE. The results are shown in Table 1.

Table 1 - Changing the shine and color characteristics of coatings

	Exposure time, h			Loss of shine,%	Color coordinate - L	Color coordinate - a	Color coordinate -b.	Changing the color Δ E to the standard
		Before testing	After testing

The samples from 1 to 4 are considered to be the tests.

Data is given for sample No. 4 - 144 hours UV irradiation, which corresponds to GOST 30973-2002 (40 conditional years):

L \u003d 4.25 norm 5.5; a \u003d 0.48 norm 0.80; B \u003d 1.54 norm 3.5.

Conclusion:

The power of the luminous flux to 80 ± 5 W / m 2 leads to a sharp drop in the shine of coatings by 98% after 36 hours of tests as a result of the formation of plaque. With the continuation of the tests, the further loss of shine does not occur. Light resistance can be described in accordance with GOST 30973-2002 - 40 conditions.

Color characteristics of the coating are permissible and correspond to GOST 30973-2002 on samples No. 1, №2, №3, №4.

Acrylic in architecture

Beautiful architectural structures are created from acrylic glass - transparent roofing, facades, road fences, canopies, visors, gazebos. All these structures are operated in the open air under the constant influence of solar radiation. There is a reasonable question: whether acrylic structures can withstand the "Natisk" of the scoring sun, while maintaining excellent performance, gloss, transparency? Having rushing you: there are no reasons for concern. Acrylic structures can be safely operated on the street under the constant impact of ultraviolet radiation, even in hot countries.

Comparison Acrylic with other plastics in resistance to UV radiation

Let's try to compare acrylic with other plastics. Today, for the manufacture of facade, roof glazing and fender structures, a large number of different transparent plastics are used. At first glance, they do not differ from acrylic. But synthetic materials similar to acrylic in their visual characteristics lose their external attractiveness in several years of operation under direct sunlight. No additional coatings and films can protect low-quality plastic from ultraviolet for a long time. The material remains sensitive to UV rays, and about the reliability of all sorts of surface coatings, alas, do not have. Protection in the form of films and varnishes with time cracks, peeling. It is not surprising that the guarantee from the yellowing of such materials does not exceed several years. Plexiglas acrylic glass manifests itself completely different. The material has natural protective properties, so does not lose its excellent characteristics throughout, at least three decades.

How does the protection technology of acrylic from sun rays work?

The resistance of Plexiglas to UV radiation is ensured by the unique technology of integrated protection Naturally UV Stable. Protection is formed not only on the surface, but also throughout the structure of the material at the molecular level. The Plexigla Plexiglas manufacturer provides a 30-year warranty for the absence of yellowing and clouding at a constant operation on the street. Such a warranty applies to transparent colorless sheets, pipes, blocks, rods, corrugated and ribbed acrylic glass plates of the Plexiglas brand. Sheds, roofing coatings, transparent acrylic facades, arbors, fences and other products from plexiglas do not acquire an unpleasant yellow shade.

The scheme shows the changes in the acrylic light index during the warranty period of operation in various climatic zones. We see that the material light decreases slightly, but these are minimal, imperceptible changes in the naked eye. Reducing the lighting index by several percent can only be determined using special equipment. Visually acrylic remains pronorable transparent and brilliant.

On the chart, you can trace the dynamics of changes in the transmissibility acrylic in comparison with ordinary glass and other plastics. First, the transmissibility acrylic in the initial state above. This is the most transparent material from the famous plastics. Over time, the difference becomes more noticeable: low-quality materials are beginning to darken, tagged, and acrylic's light permeability remains at the same level. None of the famous plastics, except acrylic, can not pass 90% of light in thirty years of operation under the sun. That is why the acrylo prefers modern designers and architects when creating their best projects.

I mention about light transmission, we are talking about the safe spectrum of ultraviolet rays. The dangerous part of the spectrum of solar radiation acrylic glass is delayed. For example, in the house under an acrylic roof or in an airplane with acrylic porthoses, people are under reliable styling. For the explanation we will understand in the nature of ultraviolet radiation. The spectrum is divided into short-wave, medium-wave and long-wave radiation. Each type of radiation has a different impact on the world around. The most highly energy radiation with a short wavelength absorbed by the ozone layer of the planet is capable of damageing the DNA molecules. Middle-wave - with long-term exposure causes skin burns and depresses the basic functions of the body. The safest and even useful - long-wave radiation. Until our planet gets only part of the hazardous medium-bearing radiation and the entire long-wave spectrum. Acrylic passes a useful spectrum of UV radiation, delaying hazardous rays. This is the very important advantage of the material. The glazing of the house allows you to preserve the maximum light in the room, protecting people from the negative impact of ultraviolet.

Cable nylon ties are a universal fixation tool. They found use in many areas, including when outdoors. Outdoors, cable clamps are exposed to multiple impacts of a natural nature: precipitation, winds, summer heat, winter fitness, and most importantly - sunlight.

The sun rays are detachious for the screeds, they destroy nylon, make it fragile and reduce elasticity, leading to the loss of the main consumer properties of the product. In the conditions of the middle strip of Russia, the screed, installed on the street, already in the first 2 weeks can lose 10% of the stated strength. Wine is ultraviolet, invisible to the eye electromagnetic waves present in the daylight. It is long-wave UVA and to a lesser extent the middle-mining UVB (due to the atmosphere, only 10% reach the surface of the Earth) UV bands are responsible for the premature aging of nylon screeds.

The negative impact of UV is everywhere, even in the regions where sunny days are very small, because 80% of the rays penetrate through the clouds. The situation is aggravated in the northern regions with their long winter, since the permeability of the atmosphere for sun rays increases, and the snow reflects the rays, thereby double the UV impact.

Most suppliers offer to use a black screed, as a solution to solving the problem of aging of a nylon clamp under the influence of sunlight. These ties are as much as their analogs of neutral white, and the difference is only that to obtain a black color from the finished product as a coloring pigment in the raw material added a small amount of carbon powder or soot. This additive is so insignificant that it is not capable of protecting the product from UV destruction. Such ties are everywhere called "weather-resistant". Hoping that such a screed will be in good faith to work outdoors, it is like to try to warm up in the frost, dull only underwear.

When installing on the street, only ties made from UV-stabilized polyamide 66 are able to reliably withstand loads for a long period of time. Their service life, compared with standard screeds under the influence of ultraviolet, differs at times. The positive effect is achieved by adding special UV stabilizers in the raw materials. Scenario of the action of light stabilizers can be different: they can simply choose (absorb) light, highlighting the absorbed energy then in the form of heat; can enter into chemicals with primary decomposition products; Can slow down (inhibit) unwanted processes.

Recently, the Society (including in the scientific community) began to dominate the idea of \u200b\u200bthe universality of plastics and composites, which are expected to solve the majority of problems of traditional materials. It is believed that new types of plastics and composites will soon replace not only metals, but also glass, heat-resistant inorganic binders, building materials. A rather common is that by chemical or physicochemical modification of plastics (for example, their filling) can achieve impressive results.

In many ways it is true. However, polymers have several "Achilles Pytes", to fix that do not allow chemistry and physics of carbon and its connections. One of these problems is heat resistance and chemical resistance under the influence of the Sun and other radiation. Decide this problem UV stabilizers (UFS).

In the presence of an ubiquitous oxygen, the rays of the sun have powerful decomposing polymers with action. It is clearly visible according to the plastic products lying outdoors under the sun - first fading and whitewing, then cracking and scattering. No better, they behave in the sea: according to environmental status, sea water and the sun turn plastic products into dust, which the fish are then confused with plankton and eat (and then we eat such a fish). In general, without UFS and antiradiative additives (ARD), the polymer is not suitable for many of us the usual applications.

The polymers are sensitive to the effects of UV radiation, therefore the service life is reduced by the influence of atmospheric factors due to the lighting of the polymer. The use of a light stabilizer concentrate allows you to get products with high resistance to UV radiation and significantly increase their life. In addition, the use of UFS prevents the loss of color, clouding, the loss of mechanical properties and the formation of cracks in the finished product.

Light stabilizers are especially important in products of a large area subjected to solar or other radiation - films, sheets. The concept of "UV stabilization" means that the film over a certain period loses under the action of solar rays no more than half of its original mechanical strength. UFS, as a rule, contains 20% of the "spatially difficult" amines of the NLS (that is, the amines with a spatial structure that makes the conformational movements of molecules - it allows to stabilize the radicals, etc.) and the antioxidant.

Characteristics UV stabilizers

The mechanism of action of light stabilizers (except UFS has IR stabilizers, etc.) is complicated. They can simply choose the light, highlighting the absorbed energy then as heat; can enter into chemicals with primary decomposition products; Can slow down (inhibit) unwanted processes. There are two ways to introduce UFS: surface coating and introduction to the polymer unit. It is believed that in the block to introduce more expensive, but the action of UFS is more durable and more reliable. True, the bulk of products (for example, all Chinese) is stabilized by applying a polymer surface layer - as a rule, 40-50 μm. By the way, for a long service life (3-5 years or up to 6-10 seasons), there is not enough to add a lot of UFS, you need a sufficient thickness and margin of safety. Thus, for the service life of 3 years, the film should be a thickness of at least 120 MK, for 6-10 seasons, a three-layer material is needed to 150 MK thick, with a strengthened middle layer.

UFS can be divided into absorbers and stabilizers. Absorbers absorb radiation and convert it to heat (and their effectiveness depends on the thickness of the polymer layer, they are ineffective in very thin films). Stabilizers stabilize already emerging radicals.

The forms of polymers are sold in the CIS as stabilized (more expensive) and unstabilized (cheaper). In many ways, this explains the lower quality of cheap products-analogues from China or other countries. It is clear that polymers (films) with reduced stabilization will serve less than the deadline. For example, stability is often declared for 10 seasons, but does not indicate the degree of decrease in stability at reinforced loads. As a result, the service life is often half the claimed (ie 1-2 years).

A good example of the effect of stabilization of the polymer can be considered polycarbonate, polyethylene and films. The validity period of polycarbonate in the form of a cellular sheet ranges from 2 to 20 years, depending on the degree of stabilization. Due to the savings on stabilizers, 90% of manufacturers cannot confirm the stated duration of PC sheets (usually - 10 years). Same with films. For example, agriculture instead of 5-10 seasons withstand only 2-3, which leads to significant losses in the agricultural sector. Polyethylene without UFS does not work for a long time, because it is quickly decomposed by UV radiation (pay attention to the appearance and condition of PE products 10-15-year old). Because of this, for example, polyethylene gas or water pipes are prohibited to lay on the surface of the Earth and even indoors. Without UFS and ARD, it is not recommended to recycle such large-capacity polymers as polypropylene, polyformaldehyde, rubbers.

Quality UFS, unfortunately, is expensive (most of them are produced by branded Western firms), and because of this, many local producers save them (they should be added in the amount of 0.1-2, or even 5%). Instead of new guests, the production of 20 years ago are used in production. For comparison, the EU update standards for stabilizers takes place once every 10 years. Each of the types of UFS has features that should be considered when used. For example, the amine UFSs lead to material darkening, and it is not recommended for bright products. For them, phenolic UFS are used.

Note that the presence of UFS in polymers, especially films, is not for sure, what to remember consumers. Solid manufacturers focus on the presence of UFS in any products. Thus, Mitsubishi-Engineering Plastics states that the granules of their novarex polycarbonate contain an UV stabilizing additive, "so that cellular polycarbonate can be used for 10 years under the enhanced exposure to sunlight." An example is "closer" - the last April release of the Belarusian enterprise "Svetlogorsk-Khimvolokno" regarding the introduction of new products - PE films with UFS. In addition to explanations, why do I need a UFS, the press service of the enterprise notes: film with UFS "can have a service life of up to three seasons." Information from one of the oldest and respected in the enterprise industry (founded in 1964, produces hymvolokna, polyester textile threads, residents) shows: the consumer must monitor the presence of UFS in the polymer.

A few words about the market

The global market of light and thermostabilizers approaches $ 5 billion - more precisely, by 2018, a plank is expected to reach 4.8 billion. The largest consumer of stabilizers is the construction industry (in 2010, 85% of stabilizers were used to produce profiles, pipes and cable insulation). Taking into account the growing fashion for siding (the stability of which to light relevance is an essential condition), the share of UFS in construction can only increase. It is not surprising that in the market of light stabilizers and now there is a high demand - the largest consumer of stabilizers turned out to be the Asia-Pacific region, which accounts for up to half of global demand. This is followed by Western Europe and the United States. Then there are markets in South America, the CIS and Eastern Europe, in the Middle East - there is an increase in demand for UFS ahead of average, reaching 3.5-4.7% per year.

The world market since the 70s began to replenish offers from leading European companies. So, almost half a century, the Tinuvin brand is successfully used, to expand the production of which in 2001 the company CIBA built a new plant (in 2009, CIBA became part of BASF). IPG (International Plastic Guide) has tested and brought to the market the LightForMPP brand and spunkonda concentrate (this is a nonwoven polypropylene microporous vapor-permeable insulating material). New UFS, in addition to light-skaters, will be removed from the destructive effect of pesticides (including sulfur), which is especially important in the Agroprom. New UFSs have already begun to be supplied in the CIS (as a rule, deliveries go from Western Europe, USA and South Korea). The development of UFS is carried out by Japanese Novarex, Western Clariant, Ampacet, Chemtura, BASF. Recently, asian producers are becoming increasing influence - not only South Korean, but also Chinese.

Dmitry Severin