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Photoinitiator System (photoinitiator + system)
Selected AbstractsOnium salt reduces the inhibitory polymerization effect from an organic solvent in a model dental adhesive resinJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008Fabrício A. Ogliari Abstract This study evaluated the effect of organic solvent concentration on the polymerization kinetics for a model dental adhesive resin containing a ternary photoinitiator system. A monomer blend based on the bis-GMA, TEGDMA, and HEMA was used as a model dental adhesive resin, which was polymerized using a binary system [camphorquinone (CQ) and ethyl 4-dimethylamine benzoate (EDAB)] and a ternary system [CQ, EDAB, and diphenyliodonium hexafluorphosphate (DPIHFP)]. Additionally, these blends had 0, 10, 20, 30, and 40 wt % ethanol added. Real-time Fourier transform infrared spectroscopy was used to investigate the polymerization reaction over photoactivation time. Data were plotted, and Hill's three-parameter nonlinear regression was performed for curve fitting. The addition of a solvent to the monomer blends decreased the polymerization kinetics, directly affecting the rate of polymerization, delaying vitrification, and attenuating the Trommsdorf effect. The introduction of DPIHFP displayed a strong increase in reaction kinetics, reducing the solvent inhibition effect. After 10 s of photoactivation, the binary system obtained in 0, 10, 20, 30, and 40% of ethanol, a degree of conversion of 44.6, 26.3, 13.4, 1.15, and 0.0%, respectively, whereas when a ternary system was used, the values were 54.6, 40.5, 27.4, 14.5, and 3.4%. An improvement was observed in the polymerization kinetics of a model dental adhesive resin when using a ternary photoinitiation system, making the material less sensitive to the residual presence of a solvent before photoactivation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Vibrational spectroscopic investigation of light-induced polymerization process of epoxy resin, polytetrahydrofuran and spirobislactonePOLYMER INTERNATIONAL, Issue 7 2007Yujie Zhang Abstract The light-induced polymerization process of bisphenol F diglycidyl ether (BFDGE), 5,5,-dicarboxylic-7,7,-dioxo-2,2,-spirodi(benzotetrahydrofuran) (DCSBL) and polytetrahydrofuran (pTHF-250) was studied. 4-[(2-Hydroxytetradecyl)oxy]phenyl-phenyliodoniumhexafluoroantimonate, camphorquinone and ethyl 4-dimethylaminobenzoate were used as a photoinitiator system. The polymerization process was induced by light and monitored using Fourier transform infrared spectroscopy. A novel combination-initiation polymerization process was proposed: first, cationic copolymerization of BFDGE and pTHF-250 was initiated by the photoinitiator system and heat was released by this polymerization; then, copolymerization of BFDGE and DCSBL was induced by that heat while pTHF-250 served as an anionic initiator. Copyright © 2007 Society of Chemical Industry [source] Preparation and characterization of a water soluble methylated , -cyclodextrin/camphorquinone complex,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2009Jing Zhang Abstract A water soluble methylated , -cyclodextrin/camphorquinone (MCD/CQ) complex, based on methylated , -cyclodextrin (MCD) and camphorquinone (CQ), was prepared and its structure was characterized by FTIR, 1H-NMR, and UV,vis spectra. The photopolymerization kinetics of MCD/CQ in the water soluble monomer system was studied by Real-time Infrared spectroscopy (RT-IR). Compared to the photopolymerization carried out under nearly identical conditions but without MCD, the polymerization rate and final conversion initiated by a CQ-triethanolamine photoinitiator system were slightly lower. The effects of different MCD/CQ concentration, triethanolamine concentration, and light intensity were also studied. Copyright © 2009 John Wiley & Sons, Ltd. [source] Real-time Fourier transform infrared study of the free-radical ultraviolet-induced polymerization of a hybrid sol,gel.JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2003Abstract Free-radical photocurable hybrid sol,gel materials have gained special interest during the last decades. Compared to thermally processed materials, they present the advantages of fast curing, low energy consumption, and spatiotemporal control of the reaction. Although comprehension of the photochemical step is fundamental, little is known about the characteristic of photochemistry in this kind of material. Real-time Fourier transform infrared spectroscopy was used to study the photopolymerization of a hybrid sol,gel upon ultraviolet irradiation. Various photoinitiator systems were tested for their efficiency in inducing the polymerization of pendant polymerizable moieties anchored on a partially condensed silicate network. The presence of O2 and the nature of the polymerizable function were shown to be crucial factors in the photoinduced process. The effects of the photoinitiator concentration and light intensity were also studied. These results were explained in terms of classical kinetic models developed for all-organic photopolymers to point out the distinctive aspects related to the use of photoinitiated polymerization in hybrid sol,gel materials. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 831,840, 2003 [source] Polymeric Photoinitiator Containing In-Chain Thioxanthone and Coinitiator AminesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 6 2004Xuesong Jiang Abstract Summary: A polymeric photoinitiator (PTXP) containing in-chain thioxanthone (TX) and coinitiator amines was synthesized by step-growth polymerization, as well as low-molecular-weight model compounds. Photopolymerizations of methyl methacrylate (MMA) initiated by these photoinitiator systems were studied. Compared with corresponding low-molecular-weight model compounds, PTXP has a similar UV-vis spectrum with a red-shifted maximum absorption, and weaker fluorescence emission, and can photoinitiate the polymerization of MMA more effectively. The structure of PTXP, the photoinitiator synthesized here. [source] | ||||||||||