Date of Award

1986

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Abstract

5-Vinyl-1,3-benzodioxole, 28, 3,4-dimethoxystyrene, 29, 2,3-dimethoxystyrene, 30, 6-vinyl-1,4-benzodioxane, 31, and 4-vinyl-1,3-benzodioxole, 32 were synthesized and evaluated as poly(vinylcatechol) precursors. Four methods for preparing these monomers were explored. Dehydration of (alpha)-phenethyl alcohols was the best general procedure. Molecular weights as high as 95,000 in the case of poly(2,3-dimethoxystyrene) were achieved in the presence of free radical initiators. The kinetics of free radical polymerization of 2,3-dimethoxystyrene, 30, was studied dilatometrically and the overall rate of the reaction was found to be R(,p) + 2.53 x 10('-2) mol/L min. Radical copolymerizations of monomers 30 and 31 with styrene and methyl methacrylate were examined. The reactivity ratios of monomer 30 (M(,1)) with comonomers (M(,2)) were r(,1) = 0.69, r(,2) = 0.92 and r(,1) = 0.92, r(,2) = 0.23 respectively. Q and e values of 30 were calculated to be Q(,1) = 1.89, e(,1) = -1.48 in the styrene system and Q(,1) = 1.91, e(,1) = -0.83 in the methyl methacrylate system. The copolymerization parameters of monomer 31 were r(,1) = 1.09, r(,2) = 0.96; Q(,1) = 1.33, e(,1) = -1.00 in the first system, and r(,1) = 0.45, r(,2) = 1.05; Q(,1) = 0.45, e(,1) = -0.47 for the second system. Polystyrene grafts onto poly(vinylcatechol) precursors were also prepared. Poly(vinylcatechol) precursors were further characterized by DTA and TGA techniques; they were found to be thermally stable and decompose only at a temperature range of 360-550(DEGREES)C. Chloromethylation of poly 31 only with chloromethyl ethyl ether and subsequent quaternization were successful. Lithiation of poly 28, poly 30, and poly 31 was studied. Bromination of each poly(vinylcatechol) precursor was thoroughly examined. Phthalimidomethylation, followed by hydrazinolysis of poly 29, poly 30, poly 31 and poly 32 afforded aminomethylated polymers. Sulfonation of poly 29, poly 30, and poly 31 with chlorosulfonic acid was possible and could produce water soluble polymers. Conditions for deblocking the protecting groups to liberate the catechol functions were established. Boron trichloride in the presence of dodecyl mercaptan was found to be the most effective cleaving reagent. Subsequent oxidation of poly(3- and 4-vinylcatechols) with ceric ammonium nitrate generated poly(benzoquinones). Redox potentials of the oxidation of catechol and poly(3-vinylcatechol) were estimated. At 23(DEGREES)C, the midpotentials were found to be 764 and 707 mV respectively. At 35(DEGREES)C, while one midpoint potential, 290 mV, was observed for the polymeric catechol, two midpoint potentials, 432 and 870 mV were detected for the catechol. (Abstract shortened with permission of author.).

Pages

235

Share

COinS