02190nas a2200277   4500008004100000022001400041245007700055210006900132260007300201300001200274490000800286520122600294653003401520653002401554653001801578653001401596653002901610653002001639653003201659653002301691100002301714700002401737700002401761700001901785856010801804       2010                        eng d  a0921-510700aRing opening polymerization of dilactide using salen complex as catalyst0 aRing opening polymerization of dilactide using salen complex as   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a193-1980 v1683 a<p>The recent concerns about our environment have led to search for environmentally benign and sustainable materials that could substitute the more commonly used petroleum based materials. Biodegradable and sustainable polylactide (PLA) is becoming one of the most promising and practical materials as a partial replacement for the petroleum-based materials. The commercially available PLA is generally homochiral poly(L-lactide) (PLLA) at present because L-lactic acid with high optical purity can only be obtained in bulk by fermentation of carbohydrate. PLLA is mostly synthesized by ring opening polymerization (ROP) of homochiral L-lactide (LLA), which is a cyclic dimer of L-lactic acid. In the present work, poly(L-lactide)s were synthesized by the ring opening polymerization (ROP) of L-lactide using iron and manganese salen complexes as catalyst. The new iron and manganese salen complexes were synthesized, purified, characterized and used as catalyst for polymerization of L-lactide. The poly(L-lactide)s prepared were characterized by infrared, proton NMR spectroscopy, solution viscosity, gel permeation chromatography, thermal analysis and X-ray diffraction. (C) 2009 Elsevier B.V. All rights reserved.</p>10aGel permeation chromatography10aIron salen catalyst10aL-Lactic acid10aL-Lactide10aManganese salen catalyst10aPoly(L-lactide)10aring opening polymerization10aSolution viscosity1 aIdage, Bhaskar, B.1 aIdage, Susheela, B.1 aKasegaonkar, A., S.1 aJadhav, R., V.  uhttps://library.ncl.res.in/content/ring-opening-polymerization-dilactide-using-salen-complex-catalyst-002354nas a2200253   4500008004100000022001400041245012100055210006900176260007300245300001000318490000800328520141600336653003401752653002201786653001401808653002201822653002001844100002301864700001801887700002201905700001901927700002201946856013201968       2014                        eng d  a0011-916400aPBI-BuI and PAN-PSSALi based UF membranes: effects of solute and membrane surface interactions on rejection and flux0 aPBIBuI and PANPSSALi based UF membranes effects of solute and me  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a45-510 v3333 a<p>Ultrafiltration membrane using tert-butylpolybenzimidazole (PBI-BuI) was prepared and characterized for flux and rejection performance using Gel Permeation Chromatography (GPC). Polyethylene glycol (PEG) and polyethylene oxide (PEO) with different molecular weights were used as the solutes. While using feed solution containing mixture of PEGs, higher rejection was observed than using individual PEG. The water flux of PBI-BuI membrane after passing individual PEG solutions showed considerable (similar to 36%) reduction, which could be attributable to the PEG adsorption on the membrane pore surface. PEG adsorption was further substantiated by SEM, IR and TGA. The amphoteric nature of PBI-BuI could cause H-bonding between membrane surface and PEG molecules, leading to PEG adsorption on the membrane and pore surface. To ascertain this postulation, a study with PAN-PSSALi (which does not contain H-bonding) based UF membrane containing negatively charged -SO3- group was done. It was found that PEG adsorption in this case is not as predominant as in earlier case. This membrane showed marginal reduction in water flux of 8%, vis-a-vis 36% reduction shown by PBI-BuI based membrane. This indicated that H-bonding present in PBI-BuI is mainly responsible for the PEG adsorption on its membrane and pore surface, in spite of PEG being a neutral molecule. (C) 2013 Elsevier B.V. All rights reserved.</p>10aGel permeation chromatography10aPolybenzimidazole10aRejection10aSolute adsorption10aUltrafiltration1 aBhagat, Deepti, G.1 aMule, Bhavana1 aMandlekar, Neeraj1 aPandare, Kiran1 aKharul, Ulhas, K.  uhttps://library.ncl.res.in/content/pbi-bui-and-pan-pssali-based-uf-membranes-effects-solute-and-membrane-surface-interactions-0