Highly Conjugated Thiophene Derivatives as New Visible Light Sensitive Photoinitiators for Cationic Polymerization

Date

2010-01-12

Author

Aydogan, Binnur
Günbaş, Emrullah Görkem
Durmus, Asuman
Toppare, Levent Kamil
Yağcı, Yusuf

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

94
views

0
downloads

A visible light sensitive photoinitiator system for the cationic polymerization of typical monomers, e.g. of oxiranes such as cyclohexene oxide, of vinyl ethers such as n-butyl vinyl ether, and of other vinyl monomers such its N-vinylcarbazole, using highly conjugated thiophene derivatives is described. The cationic polymerization of these monomers was initiated at room temperature upon irradiation in the visible region (lambda(inc) = 480 nm) in CH2Cl2 solutions with 4,7-di(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)benzo-[1,2,5]thiadiazole (DTDQ) or 5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,3-di(thiophen-2-yl)quino-xaline (DTDQ) in the presence of diphenyliodonium hexafluorophosphate (Ph2I+PF6-). A feasible mechanism, as correlated with optical absorption and fluorescence spectroscopic measurements, free energy changes (Delta G), and proton Scavenging Studies, involves formation of exciplex by the absorption of light in the First Step, Subsequent electron transfer from excited DTDT or DTDQ to iodonium ion Yields radical cations of the thiophene derivatives. The resulting strong Bransted acid derived from this process catalyzes the cationic polymerization of variety of monomers.

Subject Keywords

Acylgermane-Based Photoinitiator, Long-Wavelength Photosensitizer, Cyclohexene Oxide, Pyridinium Salt, Photocleavable Structures, Radical Polymerization, Diaryliodonium Salts, Onium Salts, System, Photopolymerizations

URI

https://hdl.handle.net/11511/36595

Journal

MACROMOLECULES

DOI

https://doi.org/10.1021/ma901858p

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Liquid crystal-templated synthesis of polymeric microparticles with complex nanostructures Akdeniz, Burak; Büküşoğlu, Emre; Department of Chemical Engineering (2019) Liquid crystals (LC), when combined with photolithography, enable synthesis of microparticles with two- and three-dimensional shapes and internal complexities. We prepared films of nematic LCs using mixtures of reactive (RM257) and non-reactive mesogens (E7) with controlled alignment of LCs at the confining surfaces, photopolymerized the RM257 using a photomask, and then extracted the unreacted mesogens to yield polymeric microparticles. The extraction resulted in a controlled anisotropic shrinkage with an ...
Soluble Alkyl Substituted Poly(3,4-Propylenedioxyselenophene)s: A New Platform For Optoelectronic Materials Atak, Samed; Icli-Ozkut, Merve; Önal, Ahmet Muhtar; CİHANER, ATİLLA (Wiley, 2011-10-15) Optical and electrochemical properties of regiosymmetric and soluble alkylenedioxyselenophene-based electrochromic polymers, namely poly(3,3-dibutyl-3,4-dihydro-2H-seleno pheno [3,4-b][1,4]dioxephine) (PProDOS-C(4)), poly(3,3-dihexyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4]dioxephine) (PProDOS-C(6)), and poly(3,3-didecyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4]dioxephine) (PProDOS-C(10)), are highlighted. It is noted that these unique polymers have low bandgaps (1.57-1.65 eV), and they are exceptionally stable ...
Stepped-etching for preserving critical dimensions in through-wafer deep reactive ion etching of thick silicon Alper, Said Emre; Aydemir, A.; Akın, Tayfun (2009-06-25) This paper presents the experimental investigation of stepped deep reactive ion etching (DRIE) process in order to minimize critical-dimension (CD) variations due to local heating observed in through-wafer etch of 100 mum-thick, high aspect ratio silicon microstructures that are suspended over glass substrate. Classical methods of cooling the substrate, using a heat-sink layer, or increasing the thickness of sidewall passivation in general turns out to be insufficient for preventing excessive damage in crit...
ELECTROCHEMICAL BEHAVIOR OF MOCLOBEMIDE AT MERCURY AND GLASSY CARBON ELECTRODES AND VOLTAMMETRIC METHODS FOR ITS DETERMINATION Altunöz Erdoğan, Deniz; Tasdemir, Ibrahim Hudai; Erk, Nevin; Kilic, Esma (2011-01-01) Electrochemical oxidation and reduction properties of Moclobemide (MCB) were investigated at glassy carbon electrode (GCE) and hanging mercury drop electrode (HMDE). Diffusion-adsorption behavior and some extra electrochemical parameters such as diffusion coefficient, number of transferred electrons and proton participated to its electrode mechanisms on both electrode and surface coverage coefficient were calculated from the results of cyclic voltammetry and square-wave voltammetry. Reversible catalytic hyd...
A blue to highly transmissive soluble electrochromic polymer based on poly(3,4-propylenedioxyselenophene) with a high stability and coloration efficiency Ozkut, Merve Icli; Atak, Samed; Önal, Ahmet Muhtar; CİHANER, ATİLLA (2011-01-01) The optical and electrochemical properties of a regioregular and soluble alkylenedioxyselenophene-based electrochromic polymer, namely poly(3,3-didecyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4] dioxepine (PProDOS-C-10), which is synthesized by electrochemical polymerization, are highlighted. It is noted that this unique polymer has a low band gap (1.58 eV) and is exceptionally stable under ambient atmospheric conditions. Polymer films retain 97% of their electroactivity after 40 000 cycles. The percentage tran...

Citation Formats

B. Aydogan, E. G. Günbaş, A. Durmus, L. K. Toppare, and Y. Yağcı, “Highly Conjugated Thiophene Derivatives as New Visible Light Sensitive Photoinitiators for Cationic Polymerization,” MACROMOLECULES, pp. 101–106, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36595.