@article { ISI:000231367700009, title = {Transparent chiral polymers for optical applications}, journal = {Journal of Applied Polymer Science}, volume = {98}, number = {1}, year = {2005}, month = {OCT}, pages = {58-65}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA}, abstract = {

Optically active chiral polymers and copolymers of cholesteryl methacrylate have been studied for use in optical applications including plastic optical fibers. Homopolymers of chiral cholesteryl methacrylate with differing molecular weights and copolymers with methyl methacrylate were synthesized by free-radical copolymerization in tetrahydrofuran using azobisisobutyronitrile at 67 degrees C for 26 h. All polymers were characterized for molecular weight, glass-transition temperature, optical rotation, transparency, and refractive index and solution blended to test for compatibility with poly(methyl methacrylate). Such chiral materials are of particular interest because they offer useful polarization properties without requiring bulk orientation of the molecules. This makes it possible to produce low cost optical elements such as circularly birefringent or circularly polarizing optical elements with potential applications in polarization manipulations and sensing. (c) 2005 Wiley Periodicals, Inc.

}, keywords = {chiral, cholesteryl methacrylate, optically active, plastic optical fiber, poly(cholesteryl methacrylate), poly(cholesteryl methacrylate-co-methyl methacrylate)}, issn = {0021-8995}, doi = {10.1002/app.21983}, author = {Pujari, N. S. and Kulkarni, M. R. and Large, M. C. J. and Bassett, I. M. and Ponrathnam, S.} } @article { ISI:000241686000011, title = {Novel beaded polymers from telechelic methacrylic ether esters}, journal = {Reactive \& Functional Polymers}, volume = {66}, number = {10}, year = {2006}, month = {OCT}, pages = {1087-1096}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A series of telechelic dimethacrylic ether-esters (MEE) were prepared by solventless reaction of alpha,omega-dihydroxy poly(oxytetramethylene) (polytetrahydrofuran, PTHF) with phthalic anhydride and glycidyl methacrylate (GMA). MEE was polymerized with GMA as well as GMA-ethylene dimethacrylate (EGDM) to form porous beads. The terpolymer beads were observed using optical microscopy and SEM and characterized for internal pore volume, equilibrium volume-swelling ratio and dimethyl formamide and aqueous buffer regain. The morphology of the beads was dictated by the mole fraction and molecular weight of MEE in the feed. Porosity was found to increase with increase in molecular weight of MEE. Thus, porosity as high as 49\%, 50\% and 55\% was observed with MEE of molecular weights 1580, 2580 and 3480, respectively. At a specific terpolymerization feed ratio of monomers, the terpolymers formed transform from gel like structure into a macroporous one, with increase in molecular weight of MEE. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {ether-ester dimethacrylates, macroporous, Pore size distribution, porosity, telechelics}, issn = {1381-5148}, doi = {10.1016/j.reactfunctpolym.2006.01.020}, author = {Pujari, N. S. and Trivedi, J. and Ingavle, Ganesh C. and Ponrathnam, S.} } @article { ISI:000242209000043, title = {Poly(urethane methacrylate-co-glycidyl methacrylate)-supported-polypropylene biphasic membrane for lipase immobilization}, journal = {Journal of Membrane Science}, volume = {285}, number = {1-2}, year = {2006}, month = {NOV}, pages = {395-403}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Polypropylene (PP) was hydrophilized by coating followed by UV curing of a blend of 2-hydroxyethyl methacrylate (HEMA) terminated polyurethane prepolymer and glycidyl methacrylate (GMA). This allows formation of a hydrophobic membrane with increased surface hydrophilicity, biocompatibility and stability. Candida rugosa lipase (CRL) was covalently immobilized on this membrane using 5\% glutaraldehyde as a crosslinking agent for post immobilization stabilization of enzyme on membrane. The membrane obtained was placed in a batch membrane reactor where a model esterification of oleic acid with octanol was studied. Under optimum conditions, the biocatalytic membrane gave a specific activity of 796.27 units/mg and 90.26\% activity yield. Moreover, there was 85. 10\% retention of specific activity. The biocatalytic membrane was observed to retain about 84.23\% of its synthetic activity after six cycles. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Candida rugosa lipase, Enzyme immobilization, membrane bioreactor, urethane methacrylate}, issn = {0376-7388}, doi = {10.1016/j.memsci.2006.09.009}, author = {Pujari, N. S. and Vaidya, Bx and Bagalkote, S. and Ponrathnam, S. and Nene, Sanjay} } @article { ISI:000244413600017, title = {Spinning wave motion in frontal polymerization}, journal = {Chemical Engineering Science}, volume = {62}, number = {5}, year = {2007}, month = {MAR}, pages = {1448-1455}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

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.

}, keywords = {frontal polymerization, spinning wave, spiral motion, wave dynamics}, issn = {0009-2509}, doi = {10.1016/j.ces.2006.11.037}, author = {Inamdar, Satish R. and Pujari, N. S. and Karimi, I. A. and Ponrathnam, S. and Tayal, R. K. and Kulkarni, B. D.} }