Austrian Journal of Technical and
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Scopus, Web of ScienceAustriya-11-12,2019 (2) - копия
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- Kasimov Erkin Umaralievich-professor of a Tashkent institute Architecture and civyl ingeeniring, Abdukadirov Firdavs Bakhtiyorovich-magistr
Reference. 1.Babakulova N.B., Uysupov U.T. Some problems of increasing the fire resistance and heat resistance of concrete. Readings of A.I. Bulatov: Materials of III- International scientific and practical conference (on March 31, 2019) in 5 vol.4: Chemical technology and ecology in the oil and gas industry. Conference bulletin Krasnodar (Russia),2019. 29 Kasimov Erkin Umaralievich-professor of a Tashkent institute Architecture and civyl ingeeniring, Abdukadirov Firdavs Bakhtiyorovich-magistr of a Tashkent institute Architecture and civyl ingeeniring (Uzbekistan). E-mail:bjd1962@mail.ru Fire retardant nanocoating for wood protection Abstract: In article the disadvantages of intumescent coatings include their instability when exposed to external factors, which leads to a short exploitation period—up to 10 years. In addition, intumescent type coatings often contain halogen flame retardant agents, which form toxic thermolysis products during fire. Key words: fire, fire-retardants, flammability, smoke and toxic gases, fillers, rheological additives. The ideal fire retardant coatings for wood should show minimal spread of flame, little to no release of smoke and toxic gases, be easily applied, demonstrate good wear resistance, adhere to substrates, and provide low cost of production and application. It is this set of properties that should be given to the known IFR systems by nanosized additives. As follows from recent studies, this can be achieved by the use of nanostructured flame retardants boron nanocompounds nanooxides, nanoclays, and others, in intumescent type coatings. Since phosphorous fire retardants correspond to a wide range of chemical structures and not only inorganic phosphates incorporated as additives in polymers, combinations of nanoclays and organic phosphates, phosphinates, phosphonates, and red phosphorus were reported [1]. Some of these compounds are present as chemical groups in grafted polymers or copolymers, which can also act for some of them as reactive fire retardants. Various research work, mainly carried out in Asia, mentioning the combination of oMMT and red phosphorus [2], have studied ternary combinations of oMMT with magnesium hydroxide (MH) and red phosphorus in PA6. It is well known that MH acts mainly as a fire retardant by its endothermal decomposition and water vapor release, which occurs over the decomposition range of the polymer. A partial substitution of 2 wt% MH by oMMT (mixed intercalated and exfoliated) in the ternary blend allowed significant improvement of fire performance, observed using cone calorimeter and LOI test, to be achieved. The water vapor released makes the cross-linking and charring of PA6 easier. Moreover, red phosphorus can form polyphosphoric acid derivatives, which can react with the decomposition products of the other components and lead to a stable glassy and charred protective layer. The combinations of oMMT with aromatic phosphates such as triphenyl phosphate (TPP) and resorcinol bis(diphenylphosphate) (RDP) were investigated by [3] in PS and unsaturated vinyl ester resins. Aromatic phosphates did not influence the nanostructure created by the nanoclays. Synergistic effects on the ability to autoextinguish (UL 94 V0) were achieved in PS for phosphate loadings of 30 wt%. For vinylester resins, synergistic effects were found for HRR values with a superior effect on char formation. Table 1 shows the improvement of fire reaction achieved using the combination of oMMT and RDP: the peak of HRR is decreased and occurs over a longer time; nevertheless, total heat release (THR) does not change in comparison with RDP alone. Strategies based on reactive fire retardants associated with clays were proposed by various authors. Organophosphorus epoxy resins were synthesized by [3] through the reaction of 9,10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide with diethylene glycol ethyl ether acrylate (DGEBA) resin. Addition of 5–7.5 wt% of a MMT was added to investigate possible synergies. Cone calorimeter tests showed that the presence of 3 wt% phosphorus or 7.5 wt% 30 clay could improve pHRR values and THR for poly(diethylene glycol ethyl ether acrylate) (P- DGEBA), but no evidence for complementary effects for combinations was found (Table 2). investigated the flame-retardant effect of newly synthesized phosphorus-containing reactive amine, which can be used both as a cross-linking agent in epoxy resin and as a flame retardant. The effect of combining the organophosphorous amine with oMMT or sepiolite was also studied.A combination of this amine with 1 wt% oMMT entailed an increase in LOI from 21% to 36% in comparison with the same percentage of oMMT and reference amine without phosphorus. Similarly, with sepiolite, LOI increased from 21% to 34%. Moreover, a V-0 rating was achieved using organophosphorous amine. Table 1. Fire Reaction Data for Polyvinyl Ether (PVE) With Organomodified Montmorillonite (oMMT) and Resorcinol Bis(Diphenylphosphate) (RDP) at 35 kW/m 2 Irradiance. Download 1.6 Mb. Do'stlaringiz bilan baham: |
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