Date of Completion
Controlled radical polymerization, VDF, IDT, Hypervalent Iodides, Block Copolymers, Azides, Click Chemistry, Photochemistry
Prof. Alex Asandei
Prof. Douglas Adamson
Prof. Rajeswari Kasi
Field of Study
Doctor of Philosophy
This dissertation focuses on identification and development of new methodologies in complex polymer synthesis in relation to the living ring opening polymerization (LROP) of cyclic esters and controlled radical polymerization (CRP) of main chain fluorinated monomers.
The use of Cp2ZrHCl was evaluated as a milder route to replace the toxic Sn(oct)2 in LROP of ε-Caprolactone at 90 °C.
By contrast to typical high-temperature (100−250 °C) telo-/polymerizations of gaseous fluorinated monomers, carried out in high-pressure metal reactors, the visible light, Mn2(CO)10-/Bu6Sn2-photomediated initiation of vinylidene fluoride (bp = −83 °C) polymerization occurs readily from a variety of alkyl, semifluorinated, and perfluorinated halides at 40 °C, in low pressure glass tubes and in a variety of solvents, including water and alkyl carbonates. Perfluorinated alkyl iodide initiators also induce a controlled radical polymerization (CRP) via iodine degenerative transfer (IDT). While IDT proceeds with accumulation of the less reactive Pm-CF2-CH2-I vs the Pn-CH2-CF2-I chain ends, Mn2(CO)10/Bu6Sn2 enables their subsequent quantitative activation toward the synthesis of well-defined poly(vinylidene fluoride)block copolymers with a variety of other monomers.
Commercially available (CF3COO)2IIIIPh, (CH3COO)2IIIIPh and (CH3COO)3IV(PhCOO) are introduced as the least expensive and most convenient CF3/CF3I and CH3/CH3I precursors for metal-free, photo(trifluoro)(iodo)methylations of alkenes, as illustrated (and the first example of DMPI photolysis) by the first examples of their use as photoinitiators in the polymerization of vinylidene fluoride (VDF), which by contrast to typical high temperature, high pressure metal reactor requirements, was accomplished under very mild conditions (40 °C), in glass tubes. The practicality of HVICs in VDF-CRP was demonstrated with both external (I(CF2)6I), and in situ generated (CF3I) iodine chain transfer agents, via the first examples of I2-VDF-CRP.
The first example of azide initiated and terminated VDF polymerization was demonstrated using cerium ammonium nitrate (CAN) and sodium azide (NaN3). While typical free radical polymerization was obtained with azide radical alone, however, in the presence of external (I(CF2)6I) or in situ generated (CF3I) chain transfers agents, VDF-CRP-IDT was obtained. Further click chemistry enabled the synthesis of block copolymer.
Adebolu, Olumide Ibikunle, "New Methodologies in Controlled Polymerizations of Main Chain Fluorinated Monomers and Cyclic Esters" (2013). Doctoral Dissertations. 89.