Chemical, Physical, and Mechanical Characterization of Isocyanate Cross-linked Amine-Modified Silica Aerogels

Abstract

We describe a new mechanically strong lightweight porous composite material obtained by encapsulating the skeletal framework of amine-modified silica aerogels with polyurea. The conformal polymer coating preserves the mesoporous structure of the underlying silica framework and the thermal conductivity remains low at 0.041 + or - 0.001 W m-1k-1. The potential of the new cross-linked silica aerogels for load-carrying applications was determined through characterization of their mechanical behavior under compression, three-point bending and dynamic mechanical analysis (DMA). A primary glass transition temperature of 130 C was identified through SMA. At room temperature, result indication a hyperfoam behavior where in compression cross-lined aerogels are lineary elastic under small strains<4% and then exhibit yield behavior (until 40% strain) follwed by densification and inelastic hardening.

Department(s)

Mechanical and Aerospace Engineering

Second Department

Chemistry

Keywords and Phrases

Amine-Modified Silica Aerogels; Mesoporous Structure; Polyurea; Silica Framework

International Standard Serial Number (ISSN)

0897-4756

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2006 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Jan 2006

Link to Full Text

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