548-76-5 Purity
98%
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Specification
This work developed a novel flame-retardant coating for wood based on copper hexafluorosilicate (CuSiF6)-modified epoxy-amine composite. Compared with the unmodified epoxy-amine composite, the maximum temperature of the combustion gas of the CuSiF6-modified epoxy-amine composite was reduced by 204-327 °C, and the mass loss during combustion was reduced by 7.8-10.4%. In addition, the fire-retardant coating was applied to wood for fire tests, and the results showed that its flame retardant efficiency (FPE) could reach group I (flame retardant efficiency index ≤ 9 %).
Preparation of CuSiF6 modified flame-retardant composite coating
· The first method involves obtaining the polymer sample by mixing the flame retardant-hardener and the binder, namely the [Cu(eda) (deta)]SiF6 chelate complex with ED-20, until a dark blue thick mass is formed. This resulting polymer sample is denoted as ED/pepa/CuSiF6 (II).
· In the second method, ED-20 and pepa are stirred together for 5-10 minutes in specific ratios. Then, anhydrous copper(II) hexafluorosilicate is added to the mixture and stirred until a uniform consistency is achieved. The color change from light yellow to dark blue after adding CuSiF6 indicates the formation of the [Cu(eda)(deta)]SiF6 chelate complex due to the bonding of the inorganic copper(II) salt with pepa during the curing process of the composites.
This work demonstrates the continuous, one-step spray-drying (SD) synthesis of several members of this isoreticular MOF family, which differ in their anion pillars (XF6=[SiF6]2- and [TiF6]2-), N-donating organic ligands (pyrazine and 4,4'-bipyridine), and metal ions (M=Co, Cu, and Zn). These synthesized M-XF6-based MOFs can be considered as "ready-to-use" adsorbents for CO2 and N2 adsorption. In the synthetic example of SIFSIX-3-Cu, copper hexafluorosilicate hydrate was used as the anion pillar.
Synthesis procedure of SIFSIX-3-Cu
· The one-step SD synthesis involved atomizing two methanolic solutions at 85 °C, one containing M-SiF6 (M = Co, Cu, Zn) and the other containing pyrazine (pyz), resulting in fine powders that were collected with minimal methanol (MeOH) to prevent air sensitivity.
· In the case of SIFSIX-3-Cu, a 6 mL methanolic solution of 300 mg (1.34 mmol) of CuSiF6·H2O and a 6 mL methanolic solution of 325 mg (4.05 mmol) of pyz were simultaneously spray-dried under specific conditions to produce a blue powder of SIFSIX-3-Cu. The powder was then collected with a minimal amount of MeOH (272 mg; 55% yield based on Cu).
· To evaluate the CO2 sorption properties of the as-made SIFSIX-3-M MOFs, their performance was compared to that of their bulk counterparts. The SD-synthesized SIFSIX-3-M powders collected in methanol were directly transferred to sorption cells, dried, and evacuated for 12 hours at 65 °C before measuring their CO2 uptake at 298 K.
The monovalent anion of 1,3-bis(carboxymethyl)imidazolium combines with Cu to form a wavy 2D coordination polymer of the composition [Cu 2(imdc)2 (CH3OH)2](BF4) 2·(CH3OH)(H2O) where copper acetate-like dimers linked by imdc ligands act as 4-linked centers. The cation sheets stack on top of each other in an A,B,A,B… fashion and produce a structure containing channels parallel to the plane of the network. Tetrafluoroborate anions are located in the channels between the sheets. Upon removal of coordinating and non-coordinating solvent molecules, a single-crystal-to-single-crystal transformation occurs, yielding similar compounds, but with the BFanions now coordinated. CO isotherms measured at 258 and 273 K show only modest CO uptake, but suggest that the sheets move apart at elevated pressure to accommodate guest molecules. A compound with a composition of [Cu3(OH)2(imdc)2]·SiF6·2H2O·2MeOH with a 3D network was formed by combining copper acetate, copper hexafluorosilicate and Himdc. In this structure, infinitely parallel Cu3(OH)2 chains are connected by bridging ligands to form channels with approximately triangular cross-sections.
4 mL of aqueous solution containing Himdc (45 mg, 0.24 mmol), Cu(OAc)2·H2O (106 mg, 0.53 mmol) and copper hexafluorosilicate (48 mg, 0.23 mmol) was mixed with 3 mL of MeOH, and the reaction mixture was sealed. Light blue crystals formed within 24 hours. The crystals were collected, washed with acetone and dried in air, with a yield of 40 mg.
Copper hexafluorosilicate and 1,4-bis(4-pyridyl)-2-trifluoromethylbenzene (bpb-CF3) were reacted via liquid phase diffusion to form a porous SIFSIX-type metal-organic framework [Cu(bpb-CF3)2(SiF6)] (UTSA-121) containing functional trifluoromethyl groups. Single crystal X-ray diffraction analysis of UTSA-121 showed that bpb-CF3 can well replace the prototype bipyridine ligand to form a non-interpenetrating pcu framework that is highly porous (void fraction = 65.7%) with three-dimensional cross-channels and functionalized trifluoromethyl groups on the pore surface. In addition, IAST calculations showed that UTSA-121a has higher adsorption selectivity for C2H2 and CO2 than CH4 and N2 under ambient conditions.
Purple cubic crystals of UTSA-121 were obtained by slowly diffusing 2 mL of 1,4-bis(4-pyridyl)-2-trifluoromethylbenzene (bpb-CF3, 0.1 mmol, 30.0 mg) methanol solution into copper hexafluorosilicate hydrate (0.15 mmol, 30.9 mg) aqueous solution (2 mL) and adding a MeOH/H2O mixture (1:1, 4 mL) buffer layer. After 10 days, the purple crystals were collected, washed with methanol, and then dried (yield: 62% based on bpb-CF3). IR /cm-1 (KBr): 1617 (s), 1486 (m), 1429 (m), 1327 (s), 1279 (w), 1259 (m), 1226 (m), 1189 (m), 1121 (s), 1080 (w), 1 048(w), 1014(w), 908(w), 826(s), 729(w), 687(s), 659(s), 605(m), 578(w), 557(w), 530(w), 485(w), 469(s).