Polymer gels as precursors to high-performance materials. Final report, 1 June 1990-31 May 1993
The three types of materials covered in this investigation were (1) thermoreversible gels of organic polymers (such as polyethylene), (2) non-reversible gels obtained by the hydrolysis of organometallics and used as precursors to inorganic ceramics (silica and titania), and (3) hybrid composites prepared by having siloxane polymers present during the in-situ generation of the ceramic species. The kinetics of the gelation process were determined by measuring the shear moduli of the gels as a function of time for various compositions and catalyst concentrations. Of particular interest was the observed decreases in gelation time with increase in concentration of either catalyst (through increases in reaction rates) or polymer (through increases in the number of high molecular weight species necessary for gelation). Composites obtained by densification of the gels were characterized by NMR imaging, neutron and x-ray scattering, and impact strength measurements. The polymer components in the hybrid organic-inorganic composites was found to greatly increase their impact strengths. Gels, Gelation kinetics, Polymer-modified ceramics, Composites, Silica, Titania, Polysiloxanes, Polyethylene, NMR Imaging, Shear modulus, Impact strength.
- Research Organization:
- Cincinnati Univ., OH (United States). Dept. of Chemistry
- OSTI ID:
- 5652596
- Report Number(s):
- AD-A-270937/6/XAB; CNN: DAAL03-90-G-0131
- Country of Publication:
- United States
- Language:
- English
Similar Records
Stress-Density Variations in Alumina Sediments: Effects of Polymer Chemistry
Bridged polysilsesquioxanes: A novel class of hybrid organic-inorganic materials
Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CERAMICS
PRECURSOR
COMPOSITE MATERIALS
CHEMICAL PREPARATION
GELATION
REACTION KINETICS
CATALYSIS
GELS
IMPACT STRENGTH
IN-SITU PROCESSING
NMR IMAGING
ORGANIC POLYMERS
ORGANOMETALLIC COMPOUNDS
POLYETHYLENES
POLYMERS
SHEAR PROPERTIES
SILICA
SILOXANES
TIME DEPENDENCE
TITANIUM OXIDES
X-RAY DIFFRACTION
CHALCOGENIDES
COHERENT SCATTERING
COLLOIDS
DIAGNOSTIC TECHNIQUES
DIFFRACTION
DISPERSIONS
KINETICS
MATERIALS
MECHANICAL PROPERTIES
MINERALS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
POLYOLEFINS
PROCESSING
SCATTERING
SILICON COMPOUNDS
SILICON OXIDES
SYNTHESIS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360601* - Other Materials- Preparation & Manufacture
400201 - Chemical & Physicochemical Properties