02512nas a2200241 4500008004100000022001400041245010100055210006900156260007700225300001400302490000700316520163400323653002101957653001301978653001301991653001302004100002502017700002402042700002602066700002102092700002502113856013202138 2007 eng d a0947-653900aExhaustive analysis of frontal copolymerization of functionalized monovinyl and divinyl monomers0 aExhaustive analysis of frontal copolymerization of functionalize aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a5862-58720 v133 a

A series of copolymers of 2-hydroxyethyl methacrylate (HEMA)/ glycidyl methacrylate (GMA) and ethylene dimethacrylate (EGDM) were synthesized by frontal polymerization (FP). This study was conducted to investigate the effect of crosslink density, type and concentration of initiator, the use of a complex initiator system, porogen, and diluent on the most relevant parameters of FP, such as sustainability of the front, temperature profile, front velocity, and yield. The products were also characterized for intruded pore volume, pore-size distribution, epoxy-functionality number, and surface morphology. Higher crosslink densities (CLDs) and initiator concentration produced higher front velocities, whereas no trend in front temperature was noted. A complex initiation system was effective in stabilizing and increasing the polymerization yield. Relative to suspension polymerization (SP), FP products synthesized without a solvent were microporous, whereas micro-to-macroporous products were obtained in the presence of a solvent (for HEMA-EGDM polymers). We also present, explain, and discuss the exotic patterns observed under a microscope. We observed two basic types of spatial patterns, namely, planar and nonplanar patterns. The type of planar pattern observed under scanning electron microscopy (SEM) has a spatial impulse that appears as a loop followed by regular periodic motion in the radial and axial directions. This behavior gives rise to a repeating pattern that is a few microns thick. Also, nonplanar patterns, namely, layered concentric rings and winding staircase patterns, were observed under SEM.

10acopolymerization10apatterns10aPolymers10aporosity1 aPujari, Narahari, S.1 aInamdar, Satish, R.1 aAmbekar, Jalindar, D.1 aKulkarni, B., D.1 aPonrathnam, Surendra uhttps://library.ncl.res.in/content/exhaustive-analysis-frontal-copolymerization-functionalized-monovinyl-and-divinyl-monomers-001968nas a2200253 4500008004100000022001400041245005100055210005100106260010600157300001400263490000700277520114600284653002701430653001801457653001801475653001801493100002401511700001901535700001901554700001901573700001801592700002101610856008301631 2007 eng d a0009-250900aSpinning wave motion in frontal polymerization0 aSpinning wave motion in frontal polymerization aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAR a1448-14550 v623 a

We present a mathematical model describing dynamics of spinning waves which propagate during frontal polymerization reaction taking place in a cylindrical reactor tube. The self-organization of spatio-temporal solution of wave equations due to interplay between thermal diffusion and kinetics gives rise to pattern formation. We begin with a fundamental equation of motion of radial coordinate after defining an asymptotic phase for spinmode. The motion is analyzed near a critical (Hopf) point and a perturbation solution is used to obtain patterns for a case of preparation of poly(2-hydroxyethyl methacrylate) (PHEMA) via frontal polymerization reaction. The model uses the distance as seen in photograph taken using scanning electron microscope (SEM) from which motion begins around core of spiral and calculates pitch of spiral which matches closely with experimental observation in micrograph. Also the model predicts qualitatively the ramp wave and spiral wave motion as observed under SEM. Both these results are reported in open literature for the first time to our best knowledge. (c) 2006 Elsevier Ltd. All rights reserved.

10afrontal polymerization10aspinning wave10aspiral motion10awave dynamics1 aInamdar, Satish, R.1 aPujari, N., S.1 aKarimi, I., A.1 aPonrathnam, S.1 aTayal, R., K.1 aKulkarni, B., D. uhttps://library.ncl.res.in/content/spinning-wave-motion-frontal-polymerization01733nas a2200181 4500008004100000022001400041245004300055210004200098260007700140300001200217490000700229520113700236100002501373700002401398700002501422700002601447856007801473 2007 eng d a1022-133600aWater-triggered frontal polymerization0 aWatertriggered frontal polymerization aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJAN a109-1150 v283 a

A totally new mode of frontal polymerization (FP) of acrylamide is established which is triggered by the simple addition of a minute, specific volume of water. Experimental conditions under which this mode of polymerization yields linear and water-soluble polyacrylamide were carefully established, paving the way to synthesize commercially pertinent homo- and copolymers. A new redox couple was identified to circumvent the imidization and the ensuing gelation, hitherto associated with FP of acrylamide. Effects of reaction variables such as type and concentration of redox couple and volume of water on measurable parameters of FP such as front velocity, front temperature, shape of front and yield have been studied. Two types of redox couples are reported. Nonplanar frontal regime was observed in few redox couples. We could visually observe helical patterns with naked eyes, while layered patterns were observable under SEM. Additionally, micro-phase separation and heterogeneity in the polymer matrix was observed due to unreacted pockets of monomer which evolve via bulk mode. This nonlinear phenomenon is described.

1 aPujari, Narahari, S.1 aInamdar, Satish, R.1 aPonrathnam, Surendra1 aKulkarni, Bhaskar, D. uhttps://library.ncl.res.in/content/water-triggered-frontal-polymerization01371nas a2200229 4500008004100000022001400041245004100055210004100096260010600137300001400243490000700257520062700264653002400891653001800915653001400933653003400947100002400981700001901005700002201024700002101046856007401067 2011 eng d a0098-135400aSharp cut algorithm for optimization0 aSharp cut algorithm for optimization aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcDEC a2716-27280 v353 a

In this paper, we introduce a new cutting plane algorithm which is computationally less expensive and more efficient than Kelley's algorithm. This new cutting plane algorithm uses an intersection cut of three types of cutting planes. We find from numerical results that the global search method formed using successive linear programming and a new intersection set is at least twice as fast as Kelley's cutting planes. The necessary mathematical analysis and convergence theorem are provided. The key findings are illustrated via optimization of a cascade of three CSTRs. (C) 2010 Elsevier Ltd. All rights reserved.

10aConvergence theorem10aCutting plane10aSharp cut10aSuccessive linear programming1 aInamdar, Satish, R.1 aKarimi, I., A.1 aParulekar, S., J.1 aKulkarni, B., D. uhttps://library.ncl.res.in/content/sharp-cut-algorithm-optimization-0