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"Aerogel-like" polysiloxane-polyurethane hybrid foams with enhanced mechanical and thermal-insulating properties.
- Source :
-
Composites Science & Technology . Sep2021, Vol. 213, pN.PAG-N.PAG. 1p. - Publication Year :
- 2021
-
Abstract
- New organic-inorganic polyurethane-based hybrids with enhanced mechanical properties and thermal insulation properties are reported. Polyurethane-based hybrids are characterized by the intimate interactions of their inorganic and organic co-networks and prepared by sol-gel approach, have exhibited properties exceeding those of polyurethane foams, e.g. enhanced thermal stability, durability and thermal insulating effectiveness. However, mechanical properties have previously been poor. Here, new porous organic-inorganic materials consisting of a polyurethane network modified by in-situ formation of aerogel-like polysiloxane domains, were developed. They exhibit a multiscale-porosity which enhances the insulation, mechanical and thermal properties. The synthesis was performed through a novel stepwise process consisting of: preparation of a siloxane precursor based on methyl-triethoxysilane and tetraethoxysilane; functionalization of traditional polyol for polyurethane foams with 3-(triethoxysilanepropyl)isocyanate as coupling agent; use of suitable catalysts and silicone surfactants; and foaming with methylene-di-isocyanate compound. The siloxane precursors and coupling agent led to formation of "aerogel-like" polysiloxane domains within the walls and struts of the polyurethane foams. The synthesis method enabled increased incorporation of the "aerogel-like" polysiloxane structures into the foams, compared to literature, with 20 wt% SiO 2 , reducing thermal conductivity of the hybrid foams 30% compared with pristine polyurethane, in addition to significant improvement in thermal stability and mechanical properties. [Display omitted] [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02663538
- Volume :
- 213
- Database :
- Academic Search Index
- Journal :
- Composites Science & Technology
- Publication Type :
- Academic Journal
- Accession number :
- 151833359
- Full Text :
- https://doi.org/10.1016/j.compscitech.2021.108917