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This paper reported a polysiloxane-based photoinitiator (184-AC-Si), which was synthesized basing on traditional photoinitiator 1-hydroxy-cyclohexyl phenyl ketene (184) and polysiloxane. Its structure was confirmed by Hydrogen-1 nuclear magnetic resonance (1H NMR), real-time infrared spectroscopy and gel permeation chromatography (GPC). Ultraviolet (UV) absorption spectra of 184-AC-Si showed a red-shifted maximum absorption compared with 184. The kinetics of photopolymerization was studied by real-time infrared spectroscopy. More importantly, because of the polysiloxane-based photoinitiator had good ability to float up, which could be proved by X-ray photoelectron spectroscopy, mapping energy dispersive spectroscopy, UV absorption, and GPC measurements, a convenient and simple method for preparing gradient polymer initiated by 184-AC-Si was successfully developed. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The aim of this study was to synthesize and characterize N,NdimethacrylyethoxycarbonylethylN1,3benzodioxole 5methyleneDMEBM to replace both triethylene glycol dimethylacrylateTEGDMA as a dilute and the nonpolymerizable amine, which is added as a coinitiator in dental resin mixtures. 2,2bis42Hydroxy3methacryloxypropoxy phenylpropane BisGMA and camphorquinone CQ were used as monomer and photoinitiator in these model dental resin systems, in contrast to ethyl 4dimethylaminobenzoate EDMAB which was usually used as a coinitiator. DMEBM was synthesized via MichaelAddition reaction and characterized using 1H NMR spectroscopy. A mixture of BisGMADMEBMCQ was found to reach the double bond conversion of 67.5, slightly higher than that of BisGMATEGDMACQEDMAB 66.8 and BisGMATEGDMACQDMEBM 64.8. In addition, the glass transition temperature of BisGMATEGDMACQEDMAB 93.4°C were higher than that of BisGMATEGDMACQDMEBM 89.3 °C and BisGMADMEBMCQ 80.4°C. The water sorption and solubility of BisGMATEGDMACQDMEBM were higher than that of BisGMATEGDMACQEDMAB and BisGMADMEBMCQ. However, the values were still within the range of the ISO 4049 standards. DMEBM could be used as a potential coinitiator and diluent for dental composite. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A water soluble methylated β-cyclodextrin/camphorquinone (MCD/CQ) complex, based on methylated β-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. [ABSTRACT FROM AUTHOR]

Alicyclic hydroxy methacrylate monomer, o-hydroxycyclohexyl methacrylate (HCMA), was synthesized and characterized by Fourier transformed infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (1H-NMR). Photopolymerization kinetics of HCMA was investigated via real-time infrared spectroscopy (RT-IR). Polymeric network hydrogels based on hydroxyethyl methacrylate (HEMA) and HCMA were prepared by using the photopolymerization technique. Mechanical strength, swelling characteristic, and controlled release behavior of hydrogels with various feed compositions were studied. Poly(HEMA-co-HCMA) hydrogel had higher storage modulus than that of poly(HEMA) hydrogel as investigated by dynamic mechanical analysis (DMA). Acid orange 8 was used as a model drug for the investigation of drug release behavior of copolymeric hydrogels. Results indicated that increase in HCMA ratio in hydrogel composition could reduce the swelling rate and prolong the release time. Scanning electron microscopy (SEM) was also utilized to study the surface morphology of hydrogels, and the results indicated that HCMA content influenced pore diameter on the hydrogel surface. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A facile method for the preparation of porous ultrafine nanofibers was demonstrated. The PAN/NaHCO3 composite nanofibers were electrospun, and then NaHCO3 was removed by a selective dissolution and reaction with the solution of hydrochloric acid (10 wt%). The obtained PAN fibers showed highly porous surfaces after the extraction of NaHCO3. The structure and properties of ultrafine PAN nanofibers were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and thermogravimetry (TG). The results indicated that NaHCO3 could be introduced into the PAN solution and successfully electrospun. CO2 is released and pores are formed on the fibers. The morphology image of the fibers was detected by scanning electron microscope (SEM) and showed that many pores aligned the nanofibers. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A one-component type II photoinitiator (PDBP), based on 4-hydroxybenzophenone (HBP), acryloyl chloride, and piperazine, was synthesized and its structure was confirmed by 1H-NMR. The photopolymerization kinetics of the photoinitiator was studied by real-time Infrared spectroscopy (FT-IR). It indicated that PDBP was a more effective photoinitiator than that of BP/triethylamine (TEA). The rate of polymerization, final conversion increased and the induction period shortened with increase in PDBP concentration, light intensity, and amine concentration. The kinetics of photopolymerization for TPGDA incorporating PDBP in the presence of different tertiary amines as the initiating system indicated that the PDBP/TEA combination exhibited the highest polymerization rates among the PDBP/amine combinations. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Electrospinning provides a simple and versatile method for fabricating nanofiber mats. Electrospun fiber mat of well aligned and order architectures was often required for many applications. In this communication, biaxial orientation mats were electrospun by a novel collector consisting of two rotating disks with conductive edge. In addition, an auxiliary electrode was induced to focus the electrostatic field and force the fibers to align regularly. The biaxial orientation structure was formed with the variation of rotation speed without revolving the fiber mat during the electrospinning process, and the dates presented in this paper demonstrated that the degree of biaxial orientation strongly depended on the rotation speed. This simple method has potential applications in textile and electronic areas. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]