Article

1998 ◽  
Vol 76 (4) ◽  
pp. 371-381 ◽  
Author(s):  
Ian Manners
Keyword(s):  
Molecular Weight ◽  
Transition Metal ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Organometallic Polymer ◽  
Wide Range ◽  
Initial Discovery

Ring-opening polymerization (ROP) of strained ring-tilted metallocenophanes can be achieved thermally, via anionic or cationic initiation, or by the use of transition-metal catalysts and provides access to a wide range of high molecular weight (Mw = 105-106, Mn > 105) poly(metallocenes). These materials possess a variety of interesting properties and many are very easy to prepare. This article provides an overview of our work, giving background to and an account of the initial discovery, and discusses work on the synthesis and properties of new poly(metallocenes) and related materials with particular emphasis on recent research directions.Key words: metallocene, ring-opening polymerization, ferrocenophane, organometallic polymer.

Catalytic Ring-Opening Polymerization of Renewable Macrolactones to High Molecular Weight Polyethylene-like Polymers

2011 ◽  
Vol 44 (11) ◽  
pp. 4301-4305 ◽  
Author(s):  
Inge van der Meulen ◽  
Erik Gubbels ◽  
Saskia Huijser ◽  
Rafaël Sablong ◽  
Cor E. Koning ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization

Metathetical Degradation and Depolymerization of Unsaturated Polymers

1997 ◽  
Vol 70 (3) ◽  
pp. 519-529 ◽  
Author(s):  
J. C. Marmo ◽  
K. B. Wagener
Keyword(s):  
Molecular Weight ◽  
Transition Metal ◽  
Catalytic System ◽  
Lewis Acid ◽  
Catalyst System ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Side Reactions

Abstract The employment of transition metal catalysts has been a viable route in the degradation and depolymerization of unsaturated polymers. Initially, unsaturated polymers were degraded with a catalytic system containing a transition metal and a Lewis acid cocatalyst (WCl6/SnBu4). Degradation chemistry was effective in reducing the molecular weight of the polymer, however, the classical catalyst system induces side reactions which generates ill-defined products. These side reactions were obviated by using a preformed alkylidene without a Lewis acid cocatalyst, and perfectly difunctional telechelics were synthesized.

scholarly journals Transition-Metal-Free [3+2] Dehydration Cycloaddition of Donor-Acceptor Cyclopropanes With 2-Naphthols

2021 ◽  
Vol 9 ◽  
Author(s):  
Hua Zhao ◽  
Peng Shen ◽  
Dongru Sun ◽  
Hongbin Zhai ◽  
Yufen Zhao
Keyword(s):  
Transition Metal ◽  
Ring Opening ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Cyclization Reaction ◽  
Metal Free ◽  
Efficient Access ◽  
Donor Acceptor ◽  
Acid Catalyzed ◽  
Synthetic Application

A Brønsted acid-catalyzed domino ring-opening cyclization transformation of donor-acceptor (D-A) cyclopropanes and 2-naphthols has been developed. This formal [3+2] cyclization reaction provided novel and efficient access to the naphthalene-fused cyclopentanes in the absence of any transition-metal catalysts or additives. This robust procedure was completed smoothly on a gram-scale to afford the corresponding product with comparable efficiency. Furthermore, the synthetic application of the prepared product has been demonstrated by its transformation into a variety of synthetically useful molecules.

Solvent-assisted anionic ring opening polymerization of glycidol: Toward medium and high molecular weight hyperbranched polyglycerols

2013 ◽  
Vol 51 (12) ◽  
pp. 2614-2621 ◽  
Author(s):  
Muhammad Imran ul-haq ◽  
Rajesh A. Shenoi ◽  
Donald E. Brooks ◽  
Jayachandran N. Kizhakkedathu
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Anionic Ring

scholarly journals Glycol-functionalized ionic liquids for high-temperature enzymatic ring-opening polymerization

RSC Advances ◽  
2018 ◽  
Vol 8 (63) ◽  
pp. 36025-36033 ◽  
Author(s):  
Hua Zhao ◽  
Lennox O. Afriyie ◽  
Nathaniel E. Larm ◽  
Gary A. Baker
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Ionic Liquids ◽  
High Temperature ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
High Thermal Stability ◽  
Polymerization Reaction

New glycol-functionalized ionic liquids exhibit high thermal stability and are lipase-compatible, leading to a high molecular weight of polyester in the enzymatic ring-opening polymerization reaction.

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