SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF NEW CONJUGATED POLYMERS (CONDUCTING, PROTONATION, CONFORMATION, SCHIFF BASE).
Item
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Title
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SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF NEW CONJUGATED POLYMERS (CONDUCTING, PROTONATION, CONFORMATION, SCHIFF BASE).
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Identifier
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AAI8614711
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identifier
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8614711
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Creator
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WEI, YEN.
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Contributor
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George Odian
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Date
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1986
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Polymer
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Abstract
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Two new polymers, PMPM and PMMM, have been synthesized via an oxidative coupling polymerization of the ethynyl-terminated monomers, MPM and MMM, and characterized by means of.;elementary analysis, and IR, ('1)H and ('13)C NMR both in solid state and in solutions, and UV spectroscopy.;(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI).;The polymers are insoluble in most neutral organic solvents but they dissolve in and react with strong protonic acids besides protonation of the imine groups. Different reactions of the polymers with a variety of acids such as trifluoroacetic acid (99%), MeSO(,3)H (98%) and concentrated H(,2)SO(,4) (98%). The number average molecu- lar weights of PMPM and PMMM were determined to be 1500 and 16000, respectively, by end group analysis.;Various 4- and 4'-substituted trans-N-benzylidenaenilines were synthesized and the effects of substituents on the chemical shifts of appropriate protons were analyzed by the Hammett single parameter and Taft dual substituent parameter (DSP) techniques. It is concluded that the trans-N-benzylideneanilines in the neutral solvents have a twisted conformation but upon protonation, they have a coplanar conformation. This conclusion was further con- firmed and extended to the polymers by studies of their UV spectra. Both PMPM and PMMM exhibit superior thermal stabilities under N(,2) atmosphere. The thermal reactions in both N(,2) and air at different temperatures were studied by means of TGA,DSC and IR spectros- copy. A weight gain around 295(DEGREES)C was observed for the polymer samples in the TGA measurements and is attributed to reactions between the chemically active species generated from the diethynylene triple bonds and the atmospheric H(,2)O and/or O(,2) to yield carbonyl and other oxygen-containing groups. PMPM and MPM show narrow ESR absorptions orginated from the unpaired electrons delocalizing over a fairly large conjugated system. Protonation causes a dramatic increase of the signal intensities owing to the conformation change. PMPM doped with I(,2) shows further increase of the signal intensity. No ESR signal was found for PMMM or MMM. Pure PMPM is an insulator, but upon protonation or doping, its conductivity increases to 10('-6) or 10('-4)Ohm('-1)cm('-1), respectively.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Chemistry
