Copolymerization of ethylene with unsaturated alcohols and methylmethacrylate using a silylated α‐diimine nickel catalyst: Molecular modeling and photodegradation studies

Abstract

In this article, the experimental results obtained in the copolymerization of ethylene with polar monomers using a silylated α‐diimine nickel catalyst are described and compared with those obtained with a non‐silylate similar one. The results show that the introduction of a siliyl group in the para‐position of the imine moiety turns the catalyst less sensitive toward polar functionalities. However, the reactivity observed in copolymerization reactions was found to be reduced both the global polymerization and incorporation rates. Molecular modeling calculation allowed us to understand both the preferred insertion mode and the intermediate product structures for E/MMA copolymerization. Photodegradation studies showed that the presence of polar groups in the copolymers increases their rate of oxidation and turn them more easily degradable. The stabilization performed by Tinuvin 770 showed that for long‐exposure times, it is not very effective regardless it is only mixed or grafted to the copolymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Easy Entry into Reduced Ar‐BIANH2 Compounds: A New Class of Quinone/Hydroquinone‐Type Redox‐Active Couples with an Easily Tunable Potential

“…Compounds of the family bis(aryl)acenaphthenequinonediimine (Ar‐BIAN) ( 1 ; see Scheme ) have been known for some time,1–3 but have been brought to the general attention only in the 90s by Elsevier and his group 4. Since then, they have found widespread use mostly as ligands for transition metals and the corresponding complexes have been employed as catalysts for a wide variety of reactions, such as alkene hydrogenation,5 polymerization,6–11 copolymerization,12–18 aziridination,19 cyclopropanation,19 and epoxidation20 alkene‐CO copolymerization,21–24 alkyne coupling in the presence of halogens or organic halides and tin compounds25–27 or just tin compounds,28 selective semihydrogenation of alkynes29 and allenes,30 allylic aminations of olefins by nitroarenes in the presence of CO,31–33 the synthesis of pyrroles and oxazines from dienes, nitroarenes and CO,34 the reduction of nitroarenes to anilines by CO/H 2 O,35–37 the hydroamination of alkynes,38 the homo‐coupling of organic halides39 and their cross‐coupling reaction with organomagnesium, ‐zinc, and ‐tin reagents,40–44 the Suzuki–Miyaura cross coupling,45 the synthesis of 4‐quinolones and 2,3‐dihydroquinolones from 2′‐nitrochalcones and CO,46, 47 the synthesis of indoles from o ‐nitrostyrenes and CO,47, 48 the Heck arylation of olefins,49, 50 and oxidative Heck reaction,51, 52 the synthesis of dihydrofurans and dihydrobenzoxepines53 and N ‐acyl vinilogous carbamic acids,54 the cyclotrimerization of alkynes,55 the click reaction,56 the dimerization of vinyl ethers to acetals,57 and the diboration of α,β‐unsaturated carbonyl compounds 58. For some of these syntheses, the use of the Ar‐BIAN ligands was instrumental in achieving a high performance of the catalytic system.…”

Microstructural study on MMA/1‐hexene copolymers made by mononuclear and dinuclear α‐diimine nickel (II) catalysts

“…[29] Copolymerization of ethylene with polar monomers (unsaturated alcohols and methyl methacrylate [MMA]) using a silylated α-diimine nickel catalyst using methylaluminoxane (MAO) cocatalyst was studied by Matos et al The α-diimine Ni complex covering -Si(t-Bu)Ph 2 group in para position of the imine moiety exhibits lower incorporation of polar monomers. [30] Avar et al investigated the copolymerization of 1-hexene with butyl acrylate and MMA (polar monomers) using α-diimine nickel (II) catalyst activated with ethyl aluminum sesquichloride (EASC) and diethylaluminum chloride (DEAC) cocatalysts. They observed the highest incorporation of butyl acrylate monomer (13.3% mol) using EASC as cocatalyst.…”

α‐Diimine nickel catalyst for copolymerization of hexene and acrylate monomers activated by different cocatalysts

“…These catalysts are able to produce highly branched PE by the chain‐walking mechanism . Several attempts have been made to incorporate polar monomers into the polyolefins chain . ε‐caprolactam and tetrahydrofuran were copolymerized with ethylene using a late transition metal catalyst precursor .…”

“…Matos et al . reported copolymerization of ethylene with unsaturated alcohols and methyl methacrylate using a silylated α‐di imine nickel catalyst . The effect of reaction temperature and comonomer concentration on the comonomer incorporation into polyethylene chain using thermal stable α‐diimine palladium catalyst was investigated by Fu et al .…”