02356nas a2200253 4500008004100000022001400041245017200055210006900227260006800296300001200364490000700376520143100383653000901814653002701823653001901850653002201869653000801891653000901899100001101908700001501919700002401934700001501958856012901973 2005 eng d a0887-624X00aIn situ polymerization of ethylene with bis(imino)pyridine iron(II) catalysts supported on clay: the synthesis and characterization of polyethylene-clay nanocomposites0 aIn situ polymerization of ethylene with bisiminopyridine ironII  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcJAN a304-3180 v433 a

Polyethylene-clay nanocomposites were synthesized by in situ polymerization with 2,6-bis[1-(2,6-diisopropylphenylimino)ethyl] pyridine iron(II) dichloride supported on a modified montmorillonite clay pretreated with methylaluminoxane (MAO). The catalysts and the obtained nanocomposites were examined with wide-angle X-ray scattering. The exfoliation of the clay was further established by transmission electron microscopy. Upon the treatment of the clay with MAO, there was an increase in the d-spacing of the clay galleries. No further increase in the d-spacing of the galleries was observed with the iron catalyst supported on the MAO-treated clay. The catalyst activity for ethylene polymerization was independent of the Al/Fe ratio. The exfoliation of the clay inside the polymer matrix depended on various parameters, such as the clay content, catalyst content, and Al/Fe ratio. The crystallinity percentage and crystallite size of the nanocomposites were affected by the degree of exfoliation of the clay. Moreover, when ethylene was polymerized with a mixture of the homogeneous iron(II) catalyst and clay, the degree of exfoliation was significantly lower than when the polymerization was performed with a preformed clay-supported catalyst. This observation suggested that in the supported catalyst, at least some of the active centers resided within the galleries of the clay. (C) 2004 Wiley Periodicals, Inc.

10aclay10aIn situ polymerization10aNanocomposites10apolyethylene (PE)10aTEM10aWAXS1 aRay, S1 aGalgali, G1 aLele, Arundhati, C.1 aSivaram, S uhttps://library.ncl.res.in/content/situ-polymerization-ethylene-bisiminopyridine-ironii-catalysts-supported-clay-synthesis-101744nas a2200241 4500008004100000022001400041245014400055210006900199260006800268300001400336490000800350520082900358653001401187653002201201653001401223653003301237100002401270700002001294700002101314700002401335700002001359856012301379 2007 eng d a0021-899500aControlled synthesis of low-molecular-weight polyethylene waxes by titanium-biphenolate-ethylaluminum sesquichloride based catalyst systems0 aControlled synthesis of lowmolecularweight polyethylene waxes by a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAY a1531-15390 v1043 a

Soluble complexes of titanium(IV) bearing sterically hindered biphenols, such as biphenol, 1,1'-methylene di-2-naphthol, 2,2'-methylene bis(4-chlorophenol), 2,2'-methylene bis(6-tert-butyl-4-ethyl phenol), and 2,2' ethylidene bis(4,6-di-tert-butyl phenol), were prepared and characterized. These catalyst precursors, formulated as [Ti((OO)-O-boolean AND)X-2], were active in the polymerization of ethylene at high temperatures in combination with ethylaluminum sesquichloride as a cocatalyst. The ultra-low-molecular-weight polyethylenes (PEs) were linear and crystalline and displayed narrow polydispersities. The catalytic polymerization leading to PE waxes in this reaction exhibited unique properties that have potential applications in surface coatings and adhesive formulations. (c) 2007 Wiley Periodicals, Inc.

10aCatalysts10apolyethylene (PE)10asynthesis10aZiegler-Natta polymerization1 aUmare, Prashant, S.1 aRao, Karumanchi1 aTembe, Gopal, L.1 aDhoble, Deepa, Arun1 aTrivedi, Bhavna uhttps://library.ncl.res.in/content/controlled-synthesis-low-molecular-weight-polyethylene-waxes-titanium-biphenolate-102005nas a2200229 4500008004100000022001400041245010700055210006900162260000800231300001100239490000800250520119300258653002501451653002401476653002101500653002201521653004101543100001701584700002401601700002501625856012501650 2020 eng d a0079-670000aUltrahigh molecular weight polyethylene: catalysis, structure, properties, processing and applications0 aUltrahigh molecular weight polyethylene catalysis structure prop cOCT a1012900 v1093 a

Ultrahigh molecular weight polyethylene (UHMWPE) belongs to an emerging class of high-performance specialty polymers with a unique set of properties and applications. The field has witnessed many scientific and technological advances in recent years. However, synthesis of UHMWPE is not a trivial exercise and presents several challenges. This review addresses these fundamental challenges and provides an overview of recent developments in the field of UHMWPE. The nature of catalysts, reaction conditions that favor its formation, their physical properties, methods of processing them into products, and their applications are discussed. Recent developments in formation of UHMWPE in a disentangled state by use of appropriate catalysts and reaction conditions are also discussed. This has elicited considerable interest as a means of enabling melt processing of UHMWPE. This review provides a comprehensive source of information and understanding of the multifaceted aspects of UHMWPE with specific reference to chemistry, catalysis, processes for manufacturing, and an analysis of catalyst structure-polymer property relationships. (C) 2020 Elsevier B.V. All rights reserved.

10aCatalysts for UHMWPE10aDisentangled UHMWPE10aEntangled UHMWPE10apolyethylene (PE)10aUltrahigh molecular weight (UHMW) PE1 aPatel, Ketan1 aChikkali, Samir, H.1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/ultrahigh-molecular-weight-polyethylene-catalysis-structure-properties-processing-and