Results 81 to 90 of about 8,053 (218)
Polímeros, 2000 Foi utilizado o sistema catalítico tipo Ziegler-Natta modificado, constituído por TiCl4/I2/Al(i-Bu)3 para a síntese de polibutadieno com alto teor de unidades 1,4-cis.
Neusa M. T. Pires +2 more
doaj +1 more source
Molecular Weight Distributions in Ideal Polymerization Reactors. An Introductory Review [PDF]
, 2011 The ultimate aim of polymerization reaction engineering is the production of polymers with tailor-made properties. An introductory review into this field is presented, with emphasis on the effects on the molar mass distribution (MMD), of the sought ...
Meira, Gregorio Raul, Oliva, H.
core
ChemistryEurope, Volume 3, Issue 6, November 11, 2025.GA: We here report the first perarylated 2,3‐diboratabutadiene dianion and its reaction with Cp2MCl2 (M = Zr, Hf) to afford unprecedented 2,3‐diboratabutadiene π‐complexes with unique coordination modes. Addition of an N‐heterocyclic carbene (NHC) to the complexes gives rise to the donor‐induced oxidation of the BB bond, resulting in two separate NHC ...
Philipp Grewelinger +3 more
wiley +1 more source
Polímeros, 2014 O objetivo deste trabalho foi estudar sistemas catalíticos ternários constituídos por versatato de neodímio, cloreto de t-butila e hidreto de di-isobutil-alumínio para a polimerização de 1,4-cis de butadieno em hexano.
Neusa Maria Tocchetto Pires +4 more
doaj +1 more source
Gas phase polymerization of ethylene with a silica-supported metallocene catalyst: influence of temperature on deactivation [PDF]
, 1997 Ethylene was polymerized at 5 bar in a stirred powder bed reactor with silica supported rac-Me2Si[Ind]2ZrCl2/methylaluminoxane (MAO) at temperatures between 40°C and 80°C using NaCl as support bed and triethylaluminium (TEA) as a scavenger for impurities.
Meier, G.B. +5 more
core +2 more sources
Direct Carboboration of Aryl Alkenes with Stable Organoborons Through Ziegler‐Type Addition
Advanced Science, Volume 12, Issue 43, November 20, 2025.The direct carboboration of vinyl arenes with benzylic boronates has been achieved using KOtBu as the catalyst. Vinylcyclopropanes and vinylcyclobutane also participate in this reaction, yielding the corresponding 1,5‐ and 1,6‐carboboration products.
Mo Yang +5 more
wiley +1 more source
Heterogeneous Distribution of Entanglements in a Nonequilibrium Polymer Melt of UHMWPE: Influence on Crystallization without and with Graphene Oxide [PDF]
, 2016 In the past, studies have been performed to follow chain dynamics in an equilibrium polymer melt using low molar mass polymers. Here we show that in linear ultrahigh molecular weight polyethylene entanglements formed during or after polymerization are ...
Dario Romano +6 more
core +4 more sources
Electronic Structure, IR and UV-Vis Spectra of Some Suggested Ziegler-Natta Catalysts
Journal of Kufa-Physics, 2018 Three aluminum metal complexes were suggested as Ziegler-Natta catalysts and studied theoretically at the ground and excited states. Becke’s three parameter exchange with Lee, Yang, and Parr correlation functional) density functional theory and SDD ...
Faeq A. AL-Temimeia, Hamid I. Abboodb
doaj +1 more source
Polímeros, 2005 Atualmente, há uma grande demanda pelo polibutadieno com alto teor de unidades 1,4-cis, devido às suas excelentes propriedades físicas, tais como alta resistência à abrasão, baixo desenvolvimento de calor, baixa resistência ao rolamento, maior ...
Denise S. S. Nunes +2 more
doaj +1 more source
CHIMIA, 1996 The insertion polymerization of propene by using chiral transition metal compounds leads to a variety of poly propene products with different stereoregularities.
Rolf Mülhaupt, Bernhard Rieger
doaj +2 more sources