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1. Synthesis of flexible polyurethane foams by the partial substitution of polyol by steatite

Author

Plínio César de Carvalho Pinto, Virginia Ribeiro da Silva, Maria Irene Yoshida, and Marcone Augusto Leal de Oliveira

Subjects
composites, foam, steatite, mechanical properties, polyurethanes, Chemical technology, TP1-1185
Abstract

Abstract This work describes the synthesis of composites steatite/flexible polyurethane by replacing 4.5 wt. % of polyol with steatite rock powder. We evaluated two mechanical properties of composites (comfort factor and support factor) for various formulations based on a fractional factorial design. The new synthesized composites showed higher support factor, greater comfort factor, and lower cost, compared to conventional flexible polyurethane foams. There is not a significant change in the chemical composition of the foams, due to substitution of 4.5 wt. % polyol by steatite. However, there was a decrease in cell size and greater interaction between the hard segments of the composite.

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2. Polyurethane foams based on modified tung oil and reinforced with rice husk ash II: Mechanical characterization

Author

Virginia Ribeiro da Silva, Pablo Marcelo Stefani, Mirna Alejandra Mosiewicki, Maria Irene Yoshida, Mercês Coelho da Silva, and Norma Esther Marcovich

Subjects
Filler (packaging), Polyurethane Foam Tung Oil Mechanical Properties, Materials science, Polymers and Plastics, Organic Chemistry, Modulus, Dynamic mechanical analysis, INGENIERÍAS Y TECNOLOGÍAS, Compuestos, Compression (physics), Husk, Viscoelasticity, chemistry.chemical_compound, Compressive strength, chemistry, purl.org/becyt/ford/2 [https], Ingeniería de los Materiales, Composite material, purl.org/becyt/ford/2.5 [https], Polyurethane
Abstract

Viscoelastic polyurethane (PU) foams based on modified tung oil, ethylene glycol and polymeric MDI, and reinforced with rice husk ash (RHA), were prepared by a free-rise pouring method and characterized in terms of density, compression and dynamic mechanical behavior. The density of foams ranged between 50 and 90 kg/m3, depending on the position of the sample with respect to the foam rise direction and filler content. As revealed by dynamic mechanical tests, the foams exhibited two different and broad thermal transitions, the temperature of their maxima depending on filler concentration. Compression modulus, compressive strength and storage modulus increase as foam density increases but decreases as rice husk ash concentration increases due to the detrimental changes induced by the filler in the foam cellular structure. However, densification strain exhibits the opposite behavior, indicating that reinforced foams can sustain slightly higher deformations without collapsing, probably due to a reduced reactivity of the components induced by the filler. © 2013 Elsevier Ltd. All rights reserved. Fil: Ribeiro Da Silva, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina. Universidade Federal de Minas Gerais; Brasil. Ministry of Education of Brazil. CAPES Foundation; Brasil Fil: Mosiewicki, Mirna Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Yoshida, Maria Irene. Universidade Federal de Minas Gerais; Brasil Fil: Coelho Da Silva, Mercês. Universidade Federal de Itajubá; Brasil Fil: Stefani, Pablo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Marcovich, Norma Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2013

3. Synthesis of flexible polyurethane foams by the partial substitution of polyol by steatite

Author

Virginia Ribeiro da Silva, Marcone Augusto Leal de Oliveira, Plínio César de Carvalho Pinto, and Maria Irene Yoshida

Subjects
Materials science, Composite number, polyurethanes, 02 engineering and technology, Partial substitution, mechanical properties, 010402 general chemistry, lcsh:Chemical technology, 01 natural sciences, composites, chemistry.chemical_compound, Polyol, Chemical Engineering (miscellaneous), lcsh:TP1-1185, Composite material, Polyurethane, chemistry.chemical_classification, Organic Chemistry, Fractional factorial design, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Lower cost, 0210 nano-technology, foam, steatite
Abstract

This work describes the synthesis of composites steatite/flexible polyurethane by replacing 4.5 wt. % of polyol with steatite rock powder. We evaluated two mechanical properties of composites (comfort factor and support factor) for various formulations based on a fractional factorial design. The new synthesized composites showed higher support factor, greater comfort factor, and lower cost, compared to conventional flexible polyurethane foams. There is not a significant change in the chemical composition of the foams, due to substitution of 4.5 wt. % polyol by steatite. However, there was a decrease in cell size and greater interaction between the hard segments of the composite.

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