Synthesis and characterization of thermally stable and/or conductive polymers

Thesis/Dissertation · Wed Jan 01 04:00:00 UTC 1992

OSTI ID:5649670

Gajiwala, H M

Eight new thermally stable polyimides were synthesized from two tricyclic heterocyclic diamines: thionine which has a phenothiazine moiety and proflavine which has an acridine unit. The polymerization reactions were optimized with respect to solvents, reaction time, reaction temperature, solid contents, etc., and their structure property relationships were studied. All these soluble polyimides have nice film forming properties. One of the polyimides containing the acridine moiety, appears to have a tendency to form a liquid crystalline state when its solution is passed through a fine capillary. All of these polyimides were thermally stable in air up to 500-550[degrees]C and up to 600[degrees]C in a nitrogen atmosphere. They have refractive indices in the range of 1.65 to 1.85 and have relatively low value of permittivity. Two other thermally stable polymers, viz., polybenzimidazole and the ladder polymer having the phenazine moiety in the backbone were also synthesized. For these polymerization reactions, tetraamino derivative of phenazine was synthesized from the commercially available diamino, dinitro derivative of benzene. The polybenzimidazole was prepared via the azomethine pathway. This polymer had an intrinsic viscosity of 0.94 in methanesulfonic acid. The nice film forming polybenzimidazole polymer was found to be thermally stable up to 400[degrees]C. The ladder type of a polymer was synthesized by condensation polymerization between tetraaminophenazine and dihydroxybenzophenone in polyphosphoric acid at an elevated temperature. The completely conjugated ladder polymer was found to be semiconducting on doping with iodine. This polymer was highly crystalline as demonstrated by its X-ray diffraction pattern. A morphology study of the polymer indicated that the material has a tendency to form dendritic crystals. The polymer was thermally stable up to about 400[degrees]C in air.

• Research Organization: Michigan Univ., Ann Arbor, MI (United States)
• OSTI ID: 5649670
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606 -- Other Materials-- Physical Properties-- (1992-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACRIDINES
AMINES
AROMATICS
AZAARENES
AZINES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL DOPING
CRYSTAL STRUCTURE
CRYSTALS
DEHYDROCYCLIZATION
DENDRITES
DIFFRACTION
ELEMENTS
FILMS
FLUIDS
HALOGENS
HETEROCYCLIC COMPOUNDS
IMIDES
IODINE
LIQUID CRYSTALS
LIQUIDS
MATERIALS
MORPHOLOGY
NONMETALS
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
ORGANIC SULFUR COMPOUNDS
PHYSICAL PROPERTIES
POLYMERIZATION
POLYMERS
PYRIDINES
REFRACTIVE INDEX
SCATTERING
SEMICONDUCTOR MATERIALS
STABILITY
STRUCTURE-ACTIVITY RELATIONSHIPS
SYNTHESIS
THIONINE
VISCOSITY
X-RAY DIFFRACTION