Accession Number : ADA305433

Title :   Semiconducting Polymers for Gas Detection.

Descriptive Note : Contractor rept.,

Corporate Author : MCDONNELL DOUGLAS CORP LONG BEACH CA DOUGLAS AIRCRAFT DIV

Personal Author(s) : Byrd, N. R. ; Sheratte, M. B.

PDF Url : ADA305433

Report Date : DEC 1975

Pagination or Media Count : 167

Abstract : Four conjugated polyenes, and two polyesters containing phthalocyanine in their backbone, were synthesized. These polymers were characterized by chemical analysis, thermogravimetric analysis, spectral analysis, and X-ray diffraction studies for crystallinity, as well as for their film-forming capability and gas/polymer interactions. Most of the polymers were relatively insensitive to water vapor up to 50 percent relative humidity, but the polyester/phthalocyanine (iron) polymer was relatively insensitive up to 100 percent RH. On the other hand, poly(p-dimethyl-aminophenylacetylene) was too conductive at 100 percent RH. Of the gases tested, the only ones that gave any evidence of interacting with the polymers were SO2, NO(x), HCN and NH3. Poly(imidazole)/thiophene responded to each of these gases at all relative humidities, while the other polymers gave varying response, depending upon the RH. Thus, since most of these gases were electron-accepting, the electron-donating character of poly(imidazole)/thiophene substantiates the concept of electronegativity being the operating principle for interaction effects. Of the six polymers prepared, poly(imidazole)/thiophene first showed a very good response to smoldering cotton, but it later became non-responsive; presumably due to oxidation effects. However, poly(imidazole)/ferrocene generally gave consistent responses. The other four did not. The reason for this is not known. jg p2

Descriptors :   *DETECTION, *POLYMERS, *SEMICONDUCTORS, *GASES, INTERACTIONS, X RAY DIFFRACTION, FILMS, IRON, OXIDATION, PHTHALOCYANINES, ELECTRON DONORS, ELECTRON ACCEPTORS, SPECTRUM ANALYSIS, CHEMICAL ANALYSIS, DIFFRACTION ANALYSIS, HUMIDITY, CRYSTALLOGRAPHY, POLYESTER PLASTICS, WATER VAPOR, COTTON, THIOPHENES, FERROCENES, THERMOGRAVIMETRIC ANALYSIS, POLYESTER FIBERS.

Subject Categories : Polymer Chemistry
      Physical Chemistry
      Crystallography
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE