Date of Award
Doctor of Philosophy (PhD)
Polymeric catechols have been synthesized by two general procedures: (a) incorporation of catechol synthons into preformed polymers, or (b) synthesis and polymerization of a monomer containing a formal-protected catechol substituent. The utilization of condensation polymers containing oxy-phenylene repeat units as alternative supports to polystyrene has been evaluated. The techniques of functionalization of the polymers via chloromethylation 1,4-bis(chloromethoxy)butane were highlighted. The effects of concentration, reaction time, and types of Lewis acid catalysts on the extent of chloromethylation were studied. Incorporation of catechol synthons such as 1,3-benzodioxole, 2,2-dimethyl-1,3-benzodioxole, or o-phenylene carbonate into the polymeric matrices having oxy-1,4-phenylene backbone via the Friedel-Crafts reactions afforded only low to moderate loadings and was often accompanied by side reactions. The halide of the chloromethyl group could be replaced quantitatively by azide, thiocyanate, xanthate, or t-butyl thiocarbonate nucleophiles. A polymer-bound catechol precursor with relatively high loadings has been prepared by nucleophilic addition of 3,4-methylenedioxybenzyl alkoxide. A protected vinyl monomer, 5-vinyl-1,3-benzodioxole (49) was prepared from either catechol or piperonal; homopolymerizations of this monomer using radical, cationic, and anionic initiators were studied. Radical copolymerization parameters of the monomer 49 (M(,1)) with methyl methacrylate (M(,2)) and with styrene (M(,2)) were r(,1) = 1.1; r(,2) =0.45 and r(,1) =1.02; r(,2) = 0.6 respectively. Based upon these results, Q and e values for 5-vinyl-1,3-benzodioxole were calculated to be Q = 2.9 and e = -1.11. Crosslinked beads (1:1:ca 0.02; 49 :styrene:divinylbenzyl chloride) were prepared and were used in subsequent chemical modifications. Boron trichloride or boron trichloride/n-butyl mercaptan have been found to be the most efficacious agents for effecting the deblocking. The resultant immobilized catechols could be oxidized to the corresponding o-benzoquinone with such oxidizing agents as hydrogen peroxide or potassium nitrosodisulfonate (Fremy's radical). Treatment of the catechol resin with BH(,3).THF produced immobilized catecholborane, which could effect the reduction of benzaldehyde and cyclohexanone. The catechol resin was elaborated with phosphorous oxychloride to an o-phenylene phosphorochloridate resin having a maximum loading of 1.431 meq/g.
Chotiwana, Supon, "Polymeric Catechols." (1983). LSU Historical Dissertations and Theses. 3838.