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        검색결과 44

        1.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polylactic acid (PLA) is often used in the preparation of environmentally friendly biodegradable polymer plastics, and how to improve the flame retardant performance of polylactic acid has been concerned by experts and scholars. Here, we provide a new idea, using bamboo activated carbon as the main material, and phytic acid, urea and Zn(NO3)2·6(H2O) as modifiers to produce a new type of carbon flame retardant. It has bamboo activated carbon as carbon source; second, it has P, N elements and metal oxides. The two synergistically play a flame retardant role on polylactic acid. The polylactic acid composite showed good thermal stability, from no grade optimization to V-0 in the UL-94 test, and the limiting oxygen index was also increased from 20.1 to 31.2%. The above tests show that bamboo activated carbon loaded with ZnO has a good flame retardant effect on polylactic acid.
        4,200원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigate the impact of Isophorone diisocyanate functionalized graphene oxide (IPDI-GO) on the flame retardancy of rigid polyurethane foam (RPUF). IPDI-GO was synthesized and introduced into the RPUF matrix. The flame retardancy of RPUF was significantly enhanced by the incorporation of IPDI-GO, as evidenced by a reduction in peak heat release rate (PHRR) by 25% and total smoke production (TSP) by 15% in comparison to pure RPUF when IPDI-GO was incorporated at 3 wt%. Scanning electron microscopy (SEM) revealed that IPDI-GO contributed to the formation of a compact, continuous char layer on the RPUF surface. This study underscores the potential of IPDI-GO as a promising flame retardant additive for RPUF.
        4,000원
        3.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to compare and analyze the flame retardant performance of Japanese cypress(Chamaecyparis obtusa) plywood, commonly used in indoor decoration, furniture, and tableware, by treating it with three different fire retardants with different primary ingredients. The experiment was conducted in compliance with Article 31, Paragraph 2 of the Enforcement Decree of the Fire Facilities Installation and Management Act and Articles 4 and 7-2 of the Flame Retardant Performance Standards. After flame time, after glow time, char length, and char area were measured. As a result, first, after flame time was measured at 0 seconds regardless of whether the flame retardant treatment was applied. Second, after glow time was relatively long, measuring 22.7 seconds without treatment, which is likely due to the weak fire resistance and high concentration of carbon monoxide generated by the chemical characteristics of the Japanese cypress itself. Third, it was confirmed that the effects of the primary ingredient, phosphorus, in the flame retardant treatment varied depending on the technological development of the manufacturers of the same species of Japanese cypress plywood. In the future, it is expected that the results of this study will provide fundamental data to select flame retardant treatments that show high flame retardant performance according to the botanical characteristics of the wood.
        4,000원
        6.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study developed a flame-retardant fiber-reinforced composite material that satisfies the required regulations of railway vehicle interior parts for the purpose of reducing weight and simplifying the production process using SMC(sheet molding compounds) composite materials. It is essential to secure flame-retardant performance that minimizes flames and smoke for the safe evacuation of passengers in case of fire for interior parts of railway vehicles. In this study, the resin for SMC was developed by adding various flame retardant materials such as vinyl ester (halogen-based and phosphorus-based) and antimony trioxide, and chopped glass fibers were used as the reinforcing material. As a result of preparing specimens for phosphorus-based and halogen-based SMC materials, and comparing the flame retardant performance, the phosphorus-based SMC material had an oxygen index of 36.1, smoke density (1minute 30 seconds, 4minutes, 10minutes) of 1.7, 51.5, 195.1. It was measured with a toxicity index of 0.05 R and average heat for sustained burning of 4.5MJ/m, which satisfies all the flame retardant standards required for interior parts of railway vehicles, and it was found that most of the performance was better than that of halogen-based SMC.
        4,000원
        7.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        After flame-retardant treatment by the two different agents, the thermal behaviors of Lyocell fibers are discussed. In this research, H3PO4 and NaCl reduced the degradation rate and increased the char yield of the Lyocell fibers, and also increased the limiting oxygen index with the char yield increased. After treatment, the integral procedure decomposition temperature and the activation energy of Lyocell fibers are significantly increased by various concentration factors. These phenomena were indicated by the dehydration, rearrangement, formation of carbonyl groups, the evolution of carbon monoxide and dioxide, and carbonaceous residue formation. These effects were indicating the slow pathway of flame retardancy for the Lyocell fibers and are attributed to the two different flame-retardant agent treatments.
        4,000원
        8.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To improve the flame retardant performance of cellulose fibers, fluorine functional groups were introduced under various controlled fluorination conditions. The properties of the fluorinated cellulose fibers were analyzed by X-ray photoelectron spectroscopy and a thermogravimetric analysis. The fluorine functional group content in the fluorinated cellulose fibers increased with an increase in the fluorination temperature. However, the fluorination reaction increased the char yield and decreased the rate of degradation of the cellulose fibers by introducing donors, enabling the formation of a thick and compact char layer. Therefore, the flame retardant properties of cellulose fibers were improved following the fluorination treatment.
        4,000원
        9.
        2018.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study aimed to prepare a novel efficient flame retardant additive for polypropylene. The new flame retardant was prepared by chemical grafting of melamine to graphene oxide with the aid of thionyl chloride. Fourier-transform infrared spectroscopy and thermogravimetric analysis proved that melamine had been successfully grafted to the graphene oxide. The modified graphene oxide was incorporated into polypropylene via solution mixing followed by anti-solvent precipitatio. Homogeneous distribution as well as exfoliation of the nanoplatelets in the polymer matrix was observed using transmission electron microscopy. Thermogravimetric analysis showed a significant improvement in the thermo-oxidative stability of the polymer after incorporating 2 wt% of the modified graphene oxide. The modified graphene oxide also enhanced the limiting oxygen index of the polymer. However, the amount of improvement was not enough for the polymer to be ranked as a self-extinguishing material. Cone calorimetry showed that incorporating 2 wt% of the modified graphene oxide lowered total heat release and the average production rate of carbon monoxide during burning of the polymer by as much as 40 and 35%, respectively. Hence, it was concluded that the new flame retardant can retard burning of the polymer efficiently and profoundly reduce suffocation risk of exposure to burning polymer byproducts.
        4,000원
        10.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Membrane structure has a number of problems in the application of a fireproof code based on general buildings codes. Thus, the fireproof code of membrane structure is necessary to activate the construction of the membrane structure. Because it requires a systematic classification of fire retardant and flame proof performance of membrane material. Fire retardant and flame proof tests are conducted on membrane materials mostly used in current construction to propose the fire and flame retardant performance criteria of membrane materials. Fire and flame retardant tests results, PTFE membrane material with the glass fiber fabric have a limit-combustible performance. PVDF membrane material with the polyester fabric does not ensure the fire retardant performance, but this membrane material has the flame retardant performance of a thick fabric. Also, ETFE does not ensure the fire retardant performance, but this membrane material has the flame retardant of a thin fabric.
        4,000원
        12.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        폴리메틸메타크릴레이트(PMMA, polymethyl methacrylate) 판재의 기존 물성에 영향을 주지 않는 범위에서 비할로겐계 난연제인 인계 난연제를 단량체인 메틸메타아크릴레이트를 괴상중합 하여 셀 주형 성형 법에 의하여 PMMA판재를 제조하였으며 난연제 함량에 따른 난연성, 가교제의 함량과 경화시간이 PMMA판재에 어떠한 영향을 미치는가를 고찰하였다. 난연제 함량이 증가할 수록 탄화길이는 감소, 차르양은 많아지며 난연 효과를 나타내었다. 또한 난연제의 함량이 증가할수록 난연성은 우수하였으나 경도가 낮아지는 경향이 있어 가교제를 3 wt.% 사용하여 경도를 증가 시켰으며, 가교제 첨가에 의해서 경화시간을 3시간에서 2시간으로 단축시킬 수 있었다.
        4,000원
        13.
        2010.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Magnesium hydroxide-melamine core-shell particles were prepared through the coating of melamine monomer on the surface of magnesium hydroxide in the presence of phosphoric acid. The melamine monomer was dissolved in hot water but recrystallized on the surface of magnesium hydroxide by quenching to room temperature in the presence of phosphoric acid. The core-shell particle was applied to low-density polyethylene/ ethylene vinyl acetate (LDPE/EVA) resin by melt-compounding at 180˚C as flame retardant. The effect of magnesium hydroxide and melamine content has been studied on the flame retardancy of the core-shell particles in LDPE/EVA resin according to the preparation process and purity of magnesium hydroxide. Magnesium hydroxide prepared with sodium hydroxide rather than with ammonia solution revealed higher flame retardancy in core-shell particles with LDPE/EVA resin. At 50 wt% loading of flame retardant, core-shell particles revealed higher flame retardancy compared to that of the exclusive magnesium hydroxide in LDPE/EVA composite, and it was possible to satisfy the V0 grade in the UL-94 vertical test. The synergistic flame retardant effect of magnesium hydroxide and melamine core-shell particles was explained as being due to the endothermic decomposition of magnesium hydroxide and melamine, which was followed by the evolution of water from the magnesium hydroxide and porous char formation due to reactive nitrogen compounds, and carbon dioxide generated from melamine.
        4,000원
        14.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Melamincyanurate(MC), as an non halogen flame retardant are used as the polymer and plastic materials. In this study, melamine and cyanuric acid were used for the synthesis of MC. The optimum condition of synthetic MC were controlled by different molar ratio of melamine to cyanuric acid. MC was modified by coupling reaction with four different agents. The influences of modified MC were based on the coupling agent types. Preparation methods are available to offer the prospect of improved morphology control deposit stability in polyol. The results reveal that glycidoxypropyltrimethoxysilane(GDS) has the best storage stability. The best properties were obtained with melamine and cyanuric acid from 1:1 molar ratio. Modification of MC through coupling agent can efficiently enhanced the deposit stability in polyol up to 30 %.
        4,000원
        15.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Different types magnesium hydroxide groups have been obtained using the hydrothermal precipitation technique from magnesium sulfate and calcium carbonate solution. The Mg atom coordinated around O atom of SO42- in another layer to form a multi-layer structure crystal. The influence of synthesis parameters on the morphological characteristics and size of magnesium hydroxide groups precipitated in aqueous were investigated such as different of additive and pH. Magnesium hydroxide groups were decomposed gradually and converted finally to MgO particles after heated in air temperature up to 1050℃. The particle size and it's distribution morphology, crystal phase and thermal behavior of the samples were characterized through XRD, SEM, EDS, and TG/DTA.
        4,000원
        16.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two component polyurethane (PU) flame retardant coatings were prepared by blending trichloro modified polyesters (TCMPs) and isophorone diisocyanate isocyanurate. TCMPs were synthesized by polycondensation of trichlorobenzoic acid (TCBA), a flame retardant component, with adipic acid, 1,4 butanediol, and trimethylolpropane. The content of TCBA was varied in 10, 20, and 30 wt% for the reaction. Theses new flame retardant coatings showed various properties comparable to other non flame retardant coatings. Moreover, we carried out the combustion test and the flammability test for our flame retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TCBA were determined as no burn. The results of flammability test for the coatings with 20 wt% and 30 wt% of TCBA contents indicated the limiting oxygen index (LOI) values of 26% and 29% respectively, which implied relatively good flame retardancy.
        4,000원
        17.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The flame-retardant coatings were prepared by blending the synthesized triphosphorus modified polyester in the previous paper and hexamethylene diisocyanate-trimer and curing it at room temperature. The characterization of the films of the prepared coatings was performed. It was confirmed that no deterioration of physical properties of PU coatings was observed with the increasing phenylphosphonic acid (PPA) contents. Flame retardancy was tested by a 45˚ Meckel burner method and LOI method. With the 45˚ Meckel burner method, CATBTP-20C and CATBTP-30C that contain 20 wt% and 30 wt% of PPA, flame retarding component, respectively, showed the first grade flame retardancy with 2.8~3.9 cm of char length ; and, with LOI method, they exhibited a good flame retardancy as a range of 30~32% of combustion values.
        4,000원
        18.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study is to enhance the flame retardancy by the synergism effect of phosphorus and bromine groups. The flame-retardant polyurethane coatings containing phosphorus and bromine compounds were synthesized. After synthesizing the intermediate products of tetramethylene bis(orthophosphate) (TBOP) and trimethylolpropane/2,3-dibromopropionic acid (2,3-DBP) [2,3-DBP-adduct], the condensation polymerization was performed with four different monomers of two intermediate products, 1,4-butanediol, and adipic acid to obtain four-components copolymer. In the condensation polymerization, the content of phosphorus was fixed to be 2wt%, and the content of 2,3-DBP that provides bromine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing phosphorus and bromine as DTBA-10C, -20C, -30C. Average molecular weight and polydispersity index of the preparation of DTBAs were decreased with increasing 2,3-DBP content because of increase of hydroxyl group that retards reaction. We found that the thermal stability of the prepared DTBAs increased with bromine content at high temperature.
        4,500원
        19.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Three phosphorus functional groups were introduced in one structural unit of polymer backbone to enhance the flame retardancy of PU coatings. In the first step, we synthesized tetramethylene bis(orthophosphate) (TBOP) that contained two phosphorus functional groups in one structural unit. In the next step, we synthesized modified polyesters (ATBTP-10C, -20C, -30C) that contained triphosphorus group using TBOP, 1,4-butanediol, trimethylolpropane, adipic acid, and another functional monomer, phenylphosphonic acid (PPA). The amount of PPA in ATBTPs was adjusted from 10 wt% to 30 wt%. The structure and characteristics of ATBTPs were examined using FT-IR, NMR, GPC, and TGA analysis. From the thermo-behavior test of diphosphorus modified polyester (ATBT) and ATBTPs, the afterglow of ATBT, ATBTP-10C, ATBTP-20C, and ATBTP-30C were 24.7, 27.1, 29.0, and 31.7%, respectively. It was found from this result that the afterglow increased with the amount of PPA component.
        4,000원
        20.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to obtain the maximum flame retardancy with the minimal deterioration of physical properties of PU flame-retardant coatings, chlorine and phosphorous functional groups were introduced into the pre-polymer of modified polyesters. In the first step, the tetramethylene bis(orthophosphate) (TBOP) and neohexanediol dichloroacetate (DCA-adduct) intermediates were synthesized. In the second step, 1,4-butanediol and adipic acid monomers were polymerized with the two kind of intermediates to obtain copolymer. The modified polyesters containing chlorine and phosphorous (ATBA-10C, -20C, and -30C) were synthesized by adjusting the contents of chlorine compound (dichloroacetic acid, 10, 20, 30 wt%) with fixed the content of phosphorous compound (2 wt%). The PU flame-retardant coatings (TTBAH -10C, -20C, and -30C) were prepared using the synthesized ATBAs and HDI-trimer as curing agent at room temperature. The physical properties of PU flame-retardant coatings with chlorine and phosphorous were inferior to those with phosphorous only and the properties were getting worse with increasing chlorine content. Flame retardancy was tested with three methods. With the vertical method, Complete combustion time of ATBAHs were 259~347 seconds, which means that the prepared coatings are good flame-retardant. With the 45˚ Meckel burner method, char lengths of the three prepared coatings were less than 2.9 cm, which indicates that the prepared coatings are 1st grade flame retardancy. With the limiting oxygen index (LOI) method, the LOI values of the three prepared coatings were in the range of 30~35%, which proves good flame retardancy of the prepared coatings. From the results of flame retardancy tests of the specimens that contain the same amounts of flame retarding compounds, it was found that the coatings containing both phosphorous and chlorine show higher flame retardancy than the coatings containing phosphorous alone. This indicates that some synergy effect of flame retardancy exists between phosphorous and chlorine.
        4,900원
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