Macroporous thermosets via chemically induced phase separation
- Swiss Federal Inst. of Tech., Lausanne (Switzerland)
- CNRS, Strasbourg (France)
- IBM Research Div., San Jose, CA (United States). Almaden Research Center
The authors have explored a new technology based on chemically induced phase separation that yields porous epoxides and cyanurates with a closed cell morphology and micrometer sized pores with a narrow pore size distribution. When the precursor monomers are cured in the presence of a low molecular weight liquid, the desired morphology results from a phase separation and a chemical quench. After phase separation, the porosity is achieved by thermal removal of the secondary liquid phase, specifically by diffusion through the crosslinked matrix. In respect to the thermodynamics and kinetics, the origin of the phase separation process can be identified as nucleation and growth. The influence of internal and external reaction parameters, such as chemical nature of the low molecular weight liquid, its concentration and the curing temperature on the final morphology are presented. Thus, the morphology can be controlled ranging from a monomodal to bimodal pore size distribution with pore sizes in between 1 to 10 {micro}m. These porous thermosets are characterized by a significantly lower density, without any loss in thermal stability compared to the neat matrix. Such new materials demonstrate great interest for lowering the dielectric constant and for improving the fundamental understanding of the role of voids in stress relaxation and toughening.
- OSTI ID:
- 462762
- Report Number(s):
- CONF-960401-; ISBN 1-55899-334-7; TRN: IM9719%%232
- Resource Relation:
- Conference: Spring meeting of the Materials Research Society (MRS), San Francisco, CA (United States), 8-12 Apr 1996; Other Information: PBD: 1996; Related Information: Is Part Of Microporous and macroporous materials; Lobo, R.F. [ed.] [Univ. of Delaware, Newark, DE (United States)]; Beck, J.S. [ed.] [Mobil Technology Co., Paulsboro, NJ (United States)]; Suib, S.L. [ed.] [Univ. of Connecticut, Storrs, CT (United States)]; Corbin, D.R. [ed.] [E.I. Dupont de Nemours and Co., Wilmington, DE (United States)]; Davis, M.E. [ed.] [California Inst. of Tech., Pasadena, CA (United States)]; Iton, L.E. [ed.] [Argonne National Lab., IL (United States)]; Zones, S.I. [ed.] [Chevron Research and Technology Co., Richmond, CA (United States)]; PB: 566 p.; Materials Research Society symposium proceedings, Volume 431
- Country of Publication:
- United States
- Language:
- English
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