02043nas a2200253 4500008004100000022001400041245008800055210006900143260007400212300000900286490000700295520112300302653003401425653001401459653002401473653003301497100002701530700003001557700001901587700001801606700001901624700002901643856011701672 2012 eng d a1022-976000aPhotopolymerization kinetics of 2-phenylethyl (meth) acrylates studied by photo DSC0 aPhotopolymerization kinetics of 2phenylethyl meth acrylates stud aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcJAN a98110 v193 a

The present work deals with the photopolymerization of 2-phenylethyl (meth)acrylates and estimation of their kinetic parameters. Formulations were made by independently homogenizing the monomers with photoinitiators of two different classes. Two different compositions of photoinitiators were used to study the effect of concentration of photoinitiator on cure kinetics. These compositions obtained were tested for photo curing performance using differential photocalorimetry (DPC) or photo DSC under polychromatic radiation. The heat flow against time was recorded for all formulations under isothermal conditions and the rates of polymerization as well as the percentage conversions were estimated. It was observed that due to a longer timescale for reaction diffusion, the methacrylate formulations showed a higher conversion than acrylate formulations. Other parameters such as induction time, maximum rate and conversion attained as well as the time to attain peak maximum were noted. The photopolymerization and kinetic estimations of the formulations including evaluation of kinetic models are discussed.

10aBimolecular termination model10aPhoto DSC10aPhotopolymerization10aVariable autocatalytic model1 aGhorpade, Ravindra, V.1 aBhosle, Sonali, Madhavrao1 aPonrathnam, S.1 aRajan, C., R.1 aChavan, Nayaku1 aHarikrishna, Reghunathan uhttps://library.ncl.res.in/content/photopolymerization-kinetics-2-phenylethyl-meth-acrylates-studied-photo-dsc-001871nas a2200229 4500008004100000022001400041245017100055210006900226260007400295300001200369490000800381520094500389653002401334653001301358653003101371653002401402100002901426700001901455700001801474700001801492856013101510 2013 eng d a1388-615000aPhotopolymerization of bis-aromatic and alicyclic based solid urethane acrylate macromonomer in the presence of large excess of reactive diluent Kinetics and modeling0 aPhotopolymerization of bisaromatic and alicyclic based solid ure aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcMAY a805-8130 v1123 a

A solid urethane acrylate macromonomer with bis-aromatic as well as alicyclic moieties was synthesized and the kinetics of photopolymerization reactions were studied in the presence of varying concentration of photoinitiator and large excess of reactive diluent using photo DSC. The studies show that the rate of maximum polymerization was found to increase with increase in concentration of photoinitiator while a decrease was observed by an increase in temperature. The final conversion showed a decrease at highest isothermal condition due to vitrification. Estimation of kinetic parameters including applicability of autocatalytic and modified autocatalytic models were investigated by nonlinear regression. It was observed that the modified models gave a better fit with the experimental data and kinetic parameters showed a decrease with increase in temperature and an increase with increase in concentration of photoinitiator.

10aAutocatalytic model10akinetics10aLevenberg-Marquardt method10aPhotopolymerization1 aHarikrishna, Reghunathan1 aPonrathnam, S.1 aRajan, C., R.1 aTambe, S., S. uhttps://library.ncl.res.in/content/photopolymerization-bis-aromatic-and-alicyclic-based-solid-urethane-acrylate-macromonomer-001996nas a2200217 4500008004100000022001400041245012300055210006900178260006900247300001200316490000700328520115900335653003401494653001301528653001701541653002401558100002901582700001901611700001801630856013001648 2014 eng d a0300-944000aPhotopolymerization kinetics of bis-aromatic based urethane acrylate macromonomers in the presence of reactive diluent0 aPhotopolymerization kinetics of bisaromatic based urethane acryl aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcJAN a225-2310 v773 a

The present work deals with the photopolymerization of bis-aromatic based urethane acrylate macromonomers in the presence of excess end capping agent as reactive diluent and estimation of their kinetic parameters. Formulations were made by independently homogenizing the macromonomers with photoinitiators of three different classes. Three different compositions of photoinitiators were used to study the effect of concentration of photoinitiator on cure kinetics. These compositions obtained were tested for photo curing performance using photo DSC under polychromatic radiation. The heat flows against time were recorded for all formulations under isothermal condition and the rates of polymerization, peak maximum times as well as the percentage conversions were estimated. It was observed that due to a longer timescale for reaction diffusion, formulations with macromonomer containing propoxylated backbone showed higher conversions than the corresponding ethoxylated analogue. The photopolymerization and kinetic estimations of the formulations including evaluation of kinetic model are discussed. (C) 2013 Elsevier B.V. All rights reserved.

10aBimolecular termination model10akinetics10aMacromonomer10aPhotopolymerization1 aHarikrishna, Reghunathan1 aPonrathnam, S.1 aRajan, C., R. uhttps://library.ncl.res.in/content/photopolymerization-kinetics-bis-aromatic-based-urethane-acrylate-macromonomers-presence-001997nas a2200241 4500008004100000022001400041245013000055210006900185260009200254300000800346490000700354520104500361653002001406653003301426653002401459653003001483100002901513700001901542700001901561700001801580700002901598856012801627 2014 eng d a1385-772X00aPhotopolymerization of high internal phase emulsions based on 2-ethylhexyl (meth)acrylates and ethylene glycol dimethacrylate0 aPhotopolymerization of high internal phase emulsions based on 2e a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcJAN a1-60 v173 a

Photopolymerization of high internal phase emulsions based on 2-ethylhexyl (meth)acrylates and ethylene glycol dimethacrylate was carried out in presence of low concentration of different photoinitiators. The stable emulsions obtained by mixing with individual photoinitiators were subjected to low-intensity photopolymerization under UV-Visible lamp. Identical samples were irradiated for differing periods ranging from 2 to 10min at an interval of 2min. The percentage conversions of each monomer in the compositions with respect to the time of irradiation were determined using gas chromatography. It was observed that the formulations containing IRGACURE 819 showed the highest conversion while that containing IRGACURE 2959 showed the least conversion. The former showed high conversion due to the proximity of the absorption maxima of photoinitiator to the major emission line of mercury spectrum at 365nm while the latter showed least conversion due to non-availability of major absorption maxima within the irradiation range.

10a(meth)acrylates10ahigh internal phase emulsion10aPhotopolymerization10aresidual monomer analysis1 aHarikrishna, Reghunathan1 aShaikh, A., W.1 aPonrathnam, S.1 aRajan, C., R.1 aBhongale, Sunil, Sitaram uhttps://library.ncl.res.in/content/photopolymerization-high-internal-phase-emulsions-based-2-ethylhexyl-methacrylates-and-002279nas a2200217 4500008004100000022001400041245011600055210006900171260007300240300001200313490000800325520144300333653002401776653001301800653003101813653002401844100002901868700001901897700001801916856012701934 2014 eng d a0168-583X00aReaction kinetics and modeling of photoinitiated cationic polymerization of an alicyclic based diglycidyl ether0 aReaction kinetics and modeling of photoinitiated cationic polyme aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a263-2680 v3183 a

Photoinitiated cationic polymerization of cycloaliphatic diepoxides had received tremendous attention, while studies with lesser polymerizable diglycidyl ethers are comparatively less reported. The present work deals with the photoinitiated cationic polymerization of cyclohexane dimethanol diglycidyl ether followed by estimation of kinetic parameters. The effects of concentration of photoinitiator and temperature on curing performance were studied using photo differential scanning calorimeter or photo DSC with polychromatic radiation. It was observed that the rate of polymerization as well as ultimate conversion increased with increasing concentration of photoinitiator and temperature. The influences of gelation as well as diffusional restrictions have remarkable effect on cure performance. The kinetic parameters as per autocatalytic kinetic model were studied by Levenberg-Marquardt nonlinear regression method instead of conventional linear method for obtaining more accurate values of apparent rate constant. It was observed that the model fits with data from initial stages to almost towards the end of the reaction. The activation energy was found to be higher than the values reported for more reactive cycloaliphatic diepoxides. The value of pre-exponential factor increased with increase in activation energy showing influence of gelation at early stages of reaction. (C) 2013 Elsevier B.V. All rights reserved.

10aAutocatalytic model10akinetics10aLevenberg-Marquardt method10aPhotopolymerization1 aHarikrishna, Reghunathan1 aPonrathnam, S.1 aTambe, S., S. uhttps://library.ncl.res.in/content/reaction-kinetics-and-modeling-photoinitiated-cationic-polymerization-alicyclic-based-001894nas a2200205 4500008004100000022001400041245015100055210006900206260007400275300001400349490000800363520107500371653001301446653002101459653001301480653001301493653002401506100002901530856012901559 2015 eng d a1388-615000aCationic photopolymerization kinetics of neat coating formulations involving poly(propylene glycol) diglycidyl ether and glycerol diglycidyl ether0 aCationic photopolymerization kinetics of neat coating formulatio aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcDEC a1445-14540 v1223 a

Kinetic analysis of formulations based on poly(propylene glycol) diglycidyl ether and glycerol diglycidyl ether was carried out using photodifferential scanning calorimeter. The effects of formulation monomer ratios at different temperatures were studied as photocalorimetric optimization studies of formulation ratios involving diglycidyl ethers are less reported. The nature of cure was found to depend more on the in situ physical parameters rather than on the mechanism of the reaction. The variations in the observed kinetic parameters can be related to interplay of mobility of reactive species, distance of counter ion and the diffusional restrictions. The final conversion was found to increase with increase in poly(propylene glycol) diglycidyl ether content, while the thermal stability increased with an increase in glycerol diglycidyl ether content. Autocatalytic kinetic model was also evaluated, and the system underwent early gelation. The studies show that the intermediate formulations are promising compositions for surface-coating applications.

10aCoatings10aDiglycidyl ether10akinetics10aPhotoDSC10aPhotopolymerization1 aHarikrishna, Reghunathan uhttps://library.ncl.res.in/content/cationic-photopolymerization-kinetics-neat-coating-formulations-involving-polypropylene-002578nas a2200217 4500008004100000022001400041245020200055210006900257260006900326300001000395490000800405520168600413653001902099653001502118653001802133653001302151653002402164653002302188100002902211856012002240 2015 eng d a1010-603000aInhibition effect of N,N-diglycidyl-4-glycidyloxy aniline on photosensitized cationic polymerization of formulations involving resorcinol diglycidyl ether and poly(propylene glycol)diglycidyl ether0 aInhibition effect of NNdiglycidyl4glycidyloxy aniline on photose aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcAPR a17-270 v3033 a

Cationic photopolymerization studies of poly(propylene glycol)diglycidyl ether with and without 25 wt% of resorcinol diglycidyl ether were carried out in presence of bis(4-methylphenyl)iodonium hexafluorophosphate as photoinitiator. Analyses were carried out using polychromatic radiation at different temperatures in a photo differential scanning calorimeter. The formulations showed an enhancement in the rate of polymerization on addition of resorcinol diglycidyl ether. The same formulations when subjected to photosensitized polymerization in presence of 1-chloro-4-propoxy-9H-thioxanthen-9-one, showed a reverse behavior in rate due to partial absorption of radiation by resorcinol diglycidyl ether. Studies carried out on by the addition of N,N-diglycidy1-4-glycidyloxy aniline as inhibitor on the photosensitized formulations showed higher scavenging activity by inhibitor. The addition of nitrogen containing epoxy monomer as inhibitor can lead to its possible crosslinking within the matrix on polymerization along with a decrease in rate of polymerization without compromising on the final observed conversion. This effect can occur readily for non vitrifying systems. Thus, this observation provides an insight into its possible usage in a rate controlled photopolymerizable epoxy formulations. The photopolymerization kinetics were found to depend on the nature of generation, propagation and scavenging of active centers which are heavily dependent on diffusional restrictions imparted by in situ viscosity of the system. The kinetic estimations as well as evaluation of autocatalytic kinetic model are investigated. (C) 2015 Elsevier B.V. All rights reserved.

10aGlycidyl ether10aInhibition10akinetic model10akinetics10aPhotopolymerization10aPhotosensitization1 aHarikrishna, Reghunathan uhttps://library.ncl.res.in/content/inhibition-effect-nn-diglycidyl-4-glycidyloxy-aniline-photosensitized-cationic-0