Results 1 to 10 of about 2,075 (218)

Evaluation of the Reactivity of Methanol and Hydrogen Sulfide Residues with the Ziegler-Natta Catalyst during Polypropylene Synthesis and Its Effects on Polymer Properties. [PDF]

open access: yesPolymers (Basel), 2023
The study focused on the evaluation of the influence of inhibitory compounds such as hydrogen sulfide (H2S) and methanol (CH3OH) on the catalytic productivity and properties of the polymers in the polymerization process with the Ziegler–Natta ...
Hernández-Fernández J   +2 more
europepmc   +2 more sources

Selective Semi‐Hydrogenation of Acetylene using a Single‐Atom Cobalt on Carbon Nitride Photocatalyst with Water as a Proton Source

open access: yesSmall Methods, Volume 10, Issue 2, 22 January 2026.
A sustainable alternative to the energy‐intensive traditional thermocatalytic hydrogenation of acetylene to ethylene is reported. The catalyst is a cobalt single‐atom catalyst supported on carbon nitride that is powered by visible light, uses water as a proton source and demonstrates high selectivity, stability, and recyclability.
Anna Fortunato   +8 more
wiley   +1 more source

Correlation Between Vinyl Content of Recycled HDPE and Polymer Degradation: An NMR Approach

open access: yesJournal of Applied Polymer Science, Volume 142, Issue 47, December 15, 2025.
The degradation behavior of high‐density polyethylene (HDPE) during recycling depends on its vinyl group content. This study shows that 1H NMR spectroscopy enables accurate assessment of vinyl groups unlike FTIR. Changes in melt flow and molecular weight with multiple processing are linked to vinyl content which could enable tailor‐made re‐additivation
Kim Hao Ng   +3 more
wiley   +1 more source

Preparation of Ultrahigh Molecular Weight Polyethylene/Graphene Nanocomposite In situ Polymerization via Spherical and Sandwich Structure Graphene/Sio2 Support

open access: yesNanoscale Research Letters, 2018
Reduced graphene oxide/SiO2 (RGO/SiO2) serving as a novel spherical support for Ziegler-Natta (Z-N) catalyst is reported. The surface and interior of the support has a porous architecture formed by RGO/SiO2 sandwich structure.
Enqi Su   +7 more
doaj   +1 more source

The Alchemist, the Scientist, and the Robot: Exploring the Potential of Human‐AI Symbiosis in Self‐Driving Polymer Laboratories

open access: yesMacromolecular Rapid Communications, Volume 46, Issue 23, December 5, 2025.
Can artificial intelligence fully replace humans in polymer discovery? How can we effectively harness AI's potential while preserving human creativity, ethics, and expertise? Does AI introduce new biases and interpretability challenges into SDL? This perspective aims to answer these important questions and advocates for symbiotic human‐AI intelligence ...
Bahar Dadfar   +2 more
wiley   +1 more source

Influência do envelhecimento de catalisadores Ziegler-Natta à base de neodímio sobre a polimerização de 1,3-butadieno Influence of ageing of neodymium based Ziegler-Natta catalyst on butadiene polymerization

open access: yesPolímeros, 2007
Catalisadores envelhecidos em diferentes tempos (0, 5, 15, 40, 80 e 160 dias) e diferentes temperaturas (10, 25 e 40 °C) foram testados na polimerização 1,4-cis do 1,3-butadieno.
Ivana L. Mello   +3 more
doaj   +1 more source

Paramagnetic species in Ziegler Natta catalysts

open access: yes, 2023
Abstract: This doctoral thesis investigates the nature and behavior of paramagnetic Ti(III) species in industrial Ziegler-Natta catalysts (ZNCs) used for the polymerization of polyethylene and polypropylene and is the result of a collaborative effort between the EPR laboratories of the University of Torino, the University of Antwerp and the Giulio ...
openaire   +2 more sources

2,3‐Diboratabutadiene Complexes of Group 4 Metals and their Donor‐Induced Oxidative Cleavage to Methyleneboranes

open access: yesChemistryEurope, 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 BB bond, resulting in two separate NHC ...
Philipp Grewelinger   +3 more
wiley   +1 more source

Principais aspectos da polimerização do 1,3-butadieno Principles aspects of butadiene 1,3 polymerization

open access: yesPolímeros, 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

Polimerização 1,4 - cis de butadieno com o sistema catalítico tetracloreto de titânio/triisobutilalumínio/iodo 1,4 cis-Polymerization of butadiene by the catalyst system titanium tetrachloride/triisobutylaluminium/iodine

open access: yesPolímeros, 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

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