A thermally insulating vermiculite nanosheet–epoxy ... serpentine and other clay minerals. 6 Vermiculite is an exciting and naturally occurring clay-based layered material. 7 It has ... nanosheets, 19 aerogels, 20 polyurethane-based vermiculite composites, 21 heterostructures 22 and clay along with polyethylenimine and chitosan ...Web
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In situ intercalative polymerization is an environmentally-friendly process to produce polymer-clay nanocomposites with good clay dispersion. In this work, quaternary ammonium salts with tertiary amine groups were synthesized to modify clay as catalytically active modifiers for polyurethanes. Polyol dispersions with the catalyst-modified …Web
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Micron and submicron-sized vermiculite lamellar particles with nanometric thickness (< 10 nm) were prepared by ultrasonic treatments (< 12 h) of aqueous and hydrogen peroxide suspensions of thermally exfoliated vermiculite. Laser granulometry characterizations showed that the particles size distribution was dependent on the …Web
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When VMT was modified by cation exchange with long-chain quaternary ammonium, the dispersion in methylene diphenyl diisocyanate (MDI) was significantly improved. …Web
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clay, perlite, vermiculite, glass wool, sand, or; volcanic ash. ... Synthetic sorbents include man-made materials that are similar to plastics, such as polyurethane, polyethylene, and polypropylene. They are designed to adsorb liquids onto their surfaces. Other synthetic sorbents include cross-linked polymers and rubber materials, which …Web
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X-ray diffraction patterns showed that the BioHDPE was intercalated between the OVMT clay galleries. BioHDPE/OVMT biocomposites containing 5 and 10 phr of OVMT clay exhibited a shear-thinning behavior and a better dispersion/distribution in the BioHDPE matrix. The biocomposite containing 10 phr of organoclay presented a percolated network ...Web
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Abstract. Vermiculite is a natural clay that has significant exfoliation characteristics. The exfoliated vermiculite has much lighter density and water retaining …Web
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Additionally, among these polymer materials, polyurethane has increasingly attracted the attention of researchers to carry out studies on PU-based polymer concrete or PU-cement concrete/mortar [6 ...Web
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One problem is loss of blowing gases, which leads to slow increase in thermal conductivity. PU composites with plate-like nanofillers create a diffusion barrier, reducing gas transport and slowing insulation aging. In this research, a new in situ intercalative polymerization is described to disperse vermiculite (VMT) in PU.Web
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Significant loss of life and property results each year from fires fueled by polyurethane found in furnishings. Established layer-by-layer flame retardant systems were combined to produce a stacked nanocoating for flame retarding polyurethane foam. A bilayer system of chitosan (CH) and vermiculite provides a nanobrick wall …Web
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Nanocomposites of rigid polyurethane foam with unmodified vermiculite clay are synthesized. The clay is dispersed either in polyol or isocyanate before …Web
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PU/VMT composites were successfully synthesized by the casting molding method. The mixture of vermiculite with PU provided good dispersion and proportionality, given the added compositions of the clay. The PU/VMT15% composite is uniform, reinforcing the cost-benefit issue with environmental and economic advantages.Web
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The effects of composite modifications were evaluated by X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), and scanning electron microscopy (SEM/EDS) applied to the flame retardancy explored by the vertical burn test. The results indicated that adding clay controlled the particle size concerning polyurethane (PU) foams.Web
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Flexible polyurethane foam (PUF) is widely used in bedding, transportation, and furniture, despite being highly flammable. In an effort to decrease the flammability of the polymer, an environmentally friendly flame retardant coating was deposited on polyurethane foam (PUF) via layer-by-layer assembly. Treated foam was subjected to …Web
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Polyurethane foam insulation rigid panels: 6.8 21 - Initial 5.5 - aged 5 to 10 years: 1.224 0.99 : Pentane expanded foam : Polyurethane spray foam insulation rigid panels, foil-faced: 7.9 - 8.4: 1.422 - 1.512 : Pentane expanded foam, presence of an air-gap may increase panel performance. RSI = 45-48 : Polyurethane foamed in place: 6.25 40: 1.125Web
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Physical and chemical properties of gamma-irradiated styrene–butadiene rubber/vermiculite clay nanocomposites modified using maleic anhydride. Polymer Bulletin 2018, 75 (8), 3587-3606. DOI: 10.1007/s00289-017-2227-4. ... Formation and characterization of polyurethane-vermiculite clay nanocomposite foams. Polymer …Web
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2. Vermiculite. Vermiculite is a silicate mineral and is ressembles perlite as a growing media that expands in very high temperature. However, it has comparatively higher cation-exchange capacity that enables it to retain nutrients for later use. Vermiculite tends to float because of its very light weight.Web
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The largest use of polyurethane (PU) is as closed cell rigid foams for thermal insulation. One problem is loss of blowing gases, which leads to slow increase in thermal conductivity. PU composites with plate-like nanofillers create a diffusion barrier, reducing gas transport and slowing insulation aging. In this research, a new in situ intercalative polymerization is …Web
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Modification with tertiary amine catalysts improves vermiculite dispersion in polyurethane via in situ intercalative polymerization. Yuqiang Qian, Wenhao Liu, Yong Tae Park, Chris I. Lindsay, Rafael Camargo ... In situ intercalative polymerization is an environmentally-friendly process to produce polymer-clay nanocomposites with good clay ...Web
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The thermal shielding behavior of this polymer/clay nanocoating makes this system very attractive in improving the fire safety of polyurethane foam used for insulating applications. Keywords: chitosan; fire protection; insulation; layer-by-layer; polyurethane foams; vermiculite.Web
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In lab tests, the flexible coating was applied to polyurethane foam, of the type that is commonly used for furniture cushions. ... (yes, tiny plates) of vermiculite clay. As the solution dries, it ...Web
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The results indicated that adding clay controlled the particle size concerning polyurethane (PU) foams. However, they exhibited spherical structures with closed cells with relatively uniform ...Web
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Scanning electron microscopy observation reveals that a two‐phase structure consisting of polypropylene–vermiculite nanocomposite and polyamide 6 is formed in the blends. The absence of vermiculite reflections in the X‐ray powder diffraction patterns indicates that the polypropylene–vermiculite phase exhibits nanocomposite …Web
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The vermiculite clay belongs to the family of 2:1 layered phyllosilicates and can result from the change of mica by the ion exchange in the tri-octahedral smectites. ... and evaluate composites of raw vermiculite (RV) or expanded vermiculite (EV) in a vegetable polyurethane resin (VPR) matrix as thermal insulation eco-bricks. First, RV …Web
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Figure 3 shows the X-ray diffraction patterns of conventional rigid polyurethane foam, vermiculite clay, and the nanocomposites with vermiculite clay. The peaks at 20 ?6.0° and 19.3° in vermiculite clay correspond to d-spacing of 10.1 and 4.6 Å, respectively. The peak ([d.sub.001]) at 10.1 Å diffuses and shifts slightly toward lower 2? …Web
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In this study, polyurethane (PU) composite foams were modified with 2 wt.% of vermiculite fillers, which were themselves modified with casein, chitosan, and potato protein. The impact of the fillers on selected properties of the obtained composites, including their rheological (foaming behavior, dynamic viscosity), thermal (temperature of thermal …Web
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In mechanical properties, about 1.4% PCL/clay in PU/clay resulted in a large increase in the elongation of PU/clay. However, when the amount of PCL/clay was 4.2%, the elongation of PU/clay was ...Web
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In the present study, the suitability of using water treatment sludge (WTS) as the main raw material and expanded vermiculite (EV) as aggregate in the production of fired bricks was investigated. Mixtures containing between 75%– WTS by weight (wt.) and 5%–25% EV by wt. were prepared at various proportions.Web
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Vermiculite is a swelling hydrous phyllosilicate clay mineral with an ideal chemical formula of (Mg 2+, Fe 2+, Fe 3+) 3 [(SiAl) 4 O 10]OH 2 ⋅4H 2 O . Vermiculite is …Web
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Vermiculite is a swelling hydrous phyllosilicate clay mineral with an ideal chemical formula of (Mg 2+, Fe 2+, Fe 3+) 3 [ (SiAl) 4 O 10 ]OH 2 ⋅4H 2 O [ 21 ]. Vermiculite is among the most commonly used …Web
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The size of the vermiculite fillers' particles was assessed by polyol dispersion (0.04 g L −1), using the dynamic light scattering method.The particle size distribution of the unmodified vermiculite filler (V) and the vermiculite fillers modified with casein (VC), chitosan (VCH), and potato protein (VPP) are presented in Figure 2.The results indicate …Web
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As vermiculite can be expanded up to 30 times its original volume when heated to 650–950 C, expanded vermiculite (EV) is often used as an additive in materials and geopolymers to obtain greater porosity and fire resistance [22–25]. Vermiculite is a swelling hydrous phyllosilicate clay mineral with an ideal chemical formula of (Mg2+, Fe2 ...Web
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In polyurethane made with this polyol, clay platelets were extensively intercalated or exfoliated. The composites showed a >270% increase in tensile modulus, …Web
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