Chemistry Commons^™

Photopolymers : Environmentally Benign Technology For A Variety Of Industries, Tatyana Tarasevich

Legacy Theses & Dissertations (2009 - 2024)

Photopolymerization is a well-known process with applications in a variety of industries. Photopolymers are formed by a reaction of monomers or oligomers, photoinitiators and in some cases crosslinkers. Upon irradiation with UV or visible light, monomers undergo conformational change to form polymers via a photochemical process. Several photopolymerization types will be discussed in this thesis. End products of photopolymerizations included epoxies, inks, coatings, photoresists, etc.

Effects Of High Pressure On Photochemical Reactivity Of Organic Molecular Materials Probed By Vibrational Spectroscopy, Jiwen Guan

Electronic Thesis and Dissertation Repository

Chemical transformations of molecular materials induced by high pressure and light radiation exhibit novel and intriguing aspects that have attracted much attention in recent years. Particularly, under the two stimuli, entire transformations of molecular species can be realized in condensed phases without employing additional chemical constraints, e.g., the need of solvents, catalysts or radical initiators. This new synthetic approach in chemistry therefore satisfies increasing need for production methods with reduced environmental impacts. Motivated by these promises, my Ph. D thesis focuses on this state-of-the-art branch of high-pressure photochemistry. Specifically, high pressure is employed to create the necessary reaction conditions to …

Functional Emulsions Via Thiol-Ene Chemistry, Douglas Amato

Dissertations

Polymer particles (micro to nano) with tunable functionality have emerged as a promising and viable technology platform for applications including coatings, cosmetics, nanomedicine, and imaging. Unfortunately, the lengthy polymerization time and lack of intrinsic functionality in the monomers used to fabricate particles is an industrial challenge. Thiol-ene chemistry cirmcumvents these limitations with very rapid polymerization kinetics, high reaction yields, with supressed side reactions and inherent functionality. This dissertation demonstrates the utility of thiol-ene/yne polymerization in miniemulsion and microfluidics to generate functional materials in a one-pot-method. The functionality is typically generated via off-stoichiometry thiol-ene (OSTE) resins which allow for either excess …

Advancing Structure-Property Relationships In Functional Materials Via Thiol-Ene Photopolymerization, Brian Richard Donovan

Dissertations

Thiol-ene photopolymerizations provide a robust and versatile synthetic pathway to functional materials, and owing to the radical step-growth nature of polymerization and the resulting homogenous network structure, provide non-convoluted insight into how network chemistry influences and dictates macromolecular properties.

The first facet of this dissertation focuses on the design and synthesis of bio-inspired, thin film adhesives for dry and aqueous adhesion. Drawing inspiration from the intertidal marine mussel, Chapter II details the synthesis of adhesive networks containing a monofunctional catechol-based monomer. The inclusion of a catechol group resulted in significant improvements in adhesion on a variety of substrates. In Chapter …

Exploring The Chemistry Of Phosphorus For Photopolymer Applications, Ryan Guterman

Electronic Thesis and Dissertation Repository

Prior to this thesis, phosphorus-containing polymers and photopolymerization represented two distinct, non-overlapping fields of study. This thesis examined the prospect of combining these two approaches to create a system possessing the benefits of both techniques. By exploiting the chemistry of phosphorus, and using photopolymerization as a fabrication method, new materials were developed and assessed for their use in various applications.

Among the many phosphorus compounds that may be used in polymer science, phosphonium salts and primary phosphines were of specific focus. First, highly fluorinated phosphonium monomers were developed to create photopolymerized hydrophobic surfaces. A structure-activity relationship was established, as both …

Photopolymerization And Characterization Of Modified Thiol-Ene Networks, Bradley James Sparks

Dissertations

Photopolymerization provides a unique ability to control variables typically uncontrollable using traditional thermally initiated polymerization, thus leading to its use in a broad range of commercial operations. Many of the traditional photopolymers suffer from several setbacks, including oxygen inhibition, unwanted stress buildup which leads to bulk shrinkage, etc., which ultimately lead to diminished polymer performance. The photopolymerization of multifunctional thiols and alkenes has been shown to provide a means to improve upon the weaknesses of traditional photoinitiated polymerizations. The free radical polymerization of thiol and –ene monomers occurs via a series of free radical chain transfer events, as a result, …

Photopolymerized Thiol-Ene Networks For Gas Barrier And Membrane Applications, Luke Kwisnek

Dissertations

Gas transport and free volume properties of photopolymerized thiol-ene networks for various applications are reported. For basic, commercially-available thiol-ene formulations, oxygen permeation was strictly dependent on the difference between T_test (room temperature for this work) and network T_g. Networks with T_g near T_test demonstrated the lowest values of permeability, diffusivity, and solubility. A robust, high-barrier network was selected for further modification. New networks with embedded functionality were formed using a two-step approach. Thio-Michael addition of a tetrathiol to monofunctional acrylates formed new functional thiol monomers. These functional thiols were combined with an isocyanurate-based triene and …

The Relationship Betweeen Dynamic And Chemical Factors On The Morphology In Aot-Water-Polymer Systems, Jolanta Elzbieta Marszalek

Dissertations

Photopolymerization of reverse microemulsion demonstrates strong influences from dynamical and chemical factors on morphology of formed polymer systems. Upon polymerization the clear microemulsion with nanoscale structures transforms into opaque films with larger aggregates that scatter light. Studied here were microemulsions based on acrylate and on thiol-ene chemistries. The difference in the two reaction mechanisms results in the phase separation occurring at different stages of the material formation. Consequently, the morphology of the material demonstrates distinct dissimilarities in the two systems. In addition, the chemical structure of the monomers promotes these morphological differences. When the microemulsion is composed of acrylate and …

Photopolymerization And Characterization Of Crosslinked Thiol-Ene Networks And Poss/Thiol-Ene Nanocomposites, Tolecia Sharonda Shaunee Clark

Dissertations

Interests in the area of thiol-ene photopolymerization are rapidly expanding due to the numerous advantages over the polymers produced by traditional solvent based polymerizations. Although current research of photoinitiated thiol-ene polymerization is diverse, numerous opportunities are available for investigating structure/property and structure/reactivity relationships and novel material applications. This research in this dissertation includes a fundamental study of the effect of monomelic thiol functionality on thiol-ene polymerization kinetics and formation of the thiol-ene network structure, and an investigation of the development of novel silicate based thiol-ene nanocomposites. The first fundamental study investigates the effect of thiol functionality on the kinetics and …