02324nas a2200265   4500008004100000022001400041245013400055210006900189260007300258300001200331490000800343520134700351653001901698653002301717653001401740653002401754653002101778653002201799653002601821100002201847700002501869700002201894700001601916856012601932       2007                        eng d  a0378-775300aHigh-temperature, polymer-graphite hybrid composites for bipolar plates: effect of processing conditions on electrical properties0 aHightemperature polymergraphite hybrid composites for bipolar pl  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a702-7070 v1633 a<p>High-temperature thermoplastic-graphite composites are prepared using polyphenylene sulfide (PPS) and polyether sulfone (PES) containing natural graphite powder. All samples are prepared by high pressure compaction and heating to high temperatures. The effect of a third additional conducting component on the electrical resistance of these composites is studied. A low resistance of the order of 0.1 Omega can be obtained even for a graphite concentration of 50% by addition of the third component. The effect of a mixing/blending technique on the anisotropy of conductivity is investigated. Solution blending of PES with graphite leads to lower anisotropy values than powder mixing and compression moulding. The samples when exposed continuously to a working temperature of 100 degrees C give a small but significant reduction in electrical resistance. X-ray diffraction studies on composites prepared by different techniques indicate that there is restructuring and crystallite re-orientation of the graphite phase in the samples. A large reduction in the crystallite size is observed for samples prepared by solution blending while re-orientation occurs after heat treatment. The changes in electrical properties can be correlated with these structural transformations in the composites. (c) 2006 Elsevier B.V. All rights reserved.</p>10abipolar plates10aconducting polymer10afuel cell10agraphite composites10ahybrid materials10apolyether sulfone10apolypherylene sulfide1 aRadhakrishnan, S.1 aRamanujam, B., T. S.1 aAdhikari, Arindam1 aSivaram, S.  uhttps://library.ncl.res.in/content/high-temperature-polymer-graphite-hybrid-composites-bipolar-plates-effect-processing-001331nas a2200169   4500008004100000022001400041245016100055210006900216260005700285300001200342490000700354520061000361100001700971700002800988700001601016856012901032       2015                        eng d  a0170-083900aHigh molecular weight polylactic acids by polyesterification using diisopropylcarbodiimide (DIPC) and 4-(dimethylamino) pyridinium ptoluene sulfonate (DPTS)0 aHigh molecular weight polylactic acids by polyesterification usi  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcMAR  a405-4150 v723 a<p>High molecular weight poly(l-lactic acid) has been prepared from the corresponding functionally terminated oligomers employing a polyesterification method at room temperature using diisopropylcarbodiimide and 4-(dimethylamino) pyridinium-p-toluene sulfonate. Self-condensation of hydroxyl and carboxylic acid-terminated poly(l-lactic acid) oligomers (M (n) : similar to 1,000) resulted in polymers with high molecular weights (M (n) &gt; 45,000) under mild conditions. End-group analysis by MALDI-TOF provided evidence for N-acylurea formation in the product under the reaction conditions employed.</p>1 aShyamroy, S.1 aGarnaik, Baijayantimala1 aSivaram, S.  uhttps://library.ncl.res.in/content/high-molecular-weight-polylactic-acids-polyesterification-using-diisopropylcarbodiimide-0