Rare earth metal initiated polymerizations of polar and nonpolar monomers to give high molecular weight polymers with extremely narrow molecular weight distribution

Yasuda, Hajime; Ihara, Eiji

doi:10.1002/macp.1995.021960802

Cited by 97 publications

(70 citation statements)

References 43 publications

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“…[1][2][3][4][5][6] The applications of new initiators, based on the lanthanide elements, has led to the production of several new macromolecular architectures like telechelic and block polymers incorporating poly(-caprolactone) (PCL) segments. [7][8][9][10] . Therefore, the development of improved structurally defined initiators of high efficiency for polylactones is of interest and, in particular, for the understanding for the design of new catalyst systems.…”

Section: Introductionmentioning

confidence: 98%

Ring-opening polymerization of ?-caprolactone and ?-valerolactone using new Sm(III) ?-halo-bis(trimethylsilyl)amido complexes

Agarwal

Karl

Dehnicke

et al. 1999

J. Appl. Polym. Sci.

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New Sm(III) -halo-bis(trimethylsilyl)amido complexes [Sm(-X) {N(SiMe 3 ) 2 } 2 (THF)] 2 (X ϭ Cl, Br) were synthesized and their crystal structures were analyzed. These complexes were used as catalysts for the homopolymerization of -caprolactone and ␦-valerolactone and found to initiate ring-opening polymerization (ROP) of these monomers in high conversion over a short period, giving homopolymers with a moderate polydispersity index (ϳ 2.0). The effect of temperature and the catalyst amount on the molecular weight distribution was also studied. Mechanistic studies were conducted using 1 : 1 and 1 : 6 molar ratios of -halo-bis-(trimethylsilyl)amido complexes and -caprolactone by 1 H-NMR and 13 C-NMR spectroscopic techniques and revealed the presence of more than one initiating species.

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Section: Introductionmentioning

confidence: 98%

Ring-opening polymerization of ?-caprolactone and ?-valerolactone using new Sm(III) ?-halo-bis(trimethylsilyl)amido complexes

Agarwal

Karl

Dehnicke

et al. 1999

J. Appl. Polym. Sci.

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“…Interestingly, syndiotacticity decreases with increasing size of the methacrylate side chain (103,105,108). More impressively, living polymerizations of alkyl acrylates (including methyl and ethyl acrylate) have been achieved, although the propagating acrylate enolates are not quite as robust as their methacrylic analogues (111,112).…”

Section: Lanthanide(iii) Initiatorsmentioning

confidence: 85%

“…Alkyl compounds such as [Cp*2SmH]2 (Cp* = C$Mq$) 9 Cp* 2 LnMe(ether), Cp* 2 LnAlMe 4 , and [Cp 2 LnMe] 2 (Ln = Sm, Y, Yb, Lu; Cp = C5H5) were found to quantitatively and quickly polymerize MMA at temperatures from -115 to 40 °C, giving polymers with PDIs as low as 1.02. The PMMA is very highly syndiotactic when produced at lower temperatures (> 96% rr at -110 °C) (102)(103)(104)(105)(106)(107)(108)(109)(110); tacticity is still quite high under more reasonable conditions (77% rr at 40 °C). Due to the solubilizing effect of the cyclopentadienyl ligands, polymerization may be carried out in a wide range of solvents, although the catalysts are extremely sensitive to air and water.…”

Section: Lanthanide(iii) Initiatorsmentioning

confidence: 99%

The Organometallic Polymerization of (Meth)acrylates: An Overview

Boffa

2000

ACS Symposium Series

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Metal-mediated (meth)acrylate polymerizations provide a good example of the versatility and importance of transition metal catalysis in polymer design. This chapter surveys several of these processes with respect to "living" behavior, experimental condition and monomer restrictions, and types of polymer architectures available.In addition to anionic methods, Group Transfer Polymerization (GTP) with silyl enolates or zirconocenes, organolanthanide-and aluminum porphyrin-initiated polymer ization, and Atom Transfer Radical Polymerization (ATRP) are discussed.Polymethacrylate and polyacrylate materials play an important role in our society. Almost two billion pounds of polymer products based on acrylic esters are produced each year for applications such as window plastics, dental materials, paints, contact lenses, fibers, and viscosity modifiers.Polymethacrylates-particularly poly(methyl methacrylate) (PMMA)-possess high strength, high impact resistance, excellent heat and chemical stability, and a highly amorphous nature which results in excellent optical clarity. For these reasons, they are used widely as building plastics (Plexiglas, Lucite). Polyacrylates are less rigid due to their lower glass transition temperatures, and as latex emulsions form the basis for durable automobile and house paints and coatings. Random copolymers of (meth)acrylates with vinylidene chloride (Sarari), acrylonitrile, and ethylene find applications as clothing fibers, tubing, gaskets, disposable gloves, and heat-and oil-resistant automotive elastomers.Despite the commercial utility of polymethacrylates and polyacrylates, refinements in synthetic methodology these macromolecules have lagged behind that of other polymers. The great majority of acrylic ester products in use today are still produced by radical polymerization, which allows little if any control over the fine points of the polymerization process. This is the result of the traditionally illcontrolled nature of acrylate polymerization. While chain termination and transfer side reactions may be largely eliminated for other monomers, such as styrene and dienes, through the use of controlled anionic polymerization, the (meth)acrylate ester

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“…Recent works have reported on the living polymerization of εCL and LA as initiated by lanthanide alkoxides. Although these initiators look very promising because of the very high polymerization rate, their selectivity appears to be much less than in the case of aluminum trialkoxides [19][20][21].…”

Section: Aluminum Alkoxides Mediated Ring Opening Polymerization Of Lmentioning

confidence: 99%

Novel Macromolecular Architectures Based on Aliphatic Polyesters: Relevance of the “Coordination-Insertion” Ring-Opening Polymerization

Mecerreyes¹,

Jérôme²,

Dubois³

Macromolecular Architectures

274

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Recent developments in the macromolecular engineering of aliphatic polyesters have been overviewed. First, aluminum alkoxides mediated living ring opening polymerization (ROP) of cyclic (di)esters, i.e., lactones, lactides, glycolide, is introduced. An insight into this so-called "coordination-insertion" mechanism and the ability of this living polymerization process to prepare well-defined homopolymers, telechelic polymers, random and block copolymers is then discussed. In the second part, the combination of the living ROP of (di)lac-tones with other well-controlled polymerization mechanisms such as anionic, cationic, free radical, and metathesis polyadditions of unsaturated comonomers, as well as polyconden-sations, is reported with special emphasis on the design of new and well-tailored macromolecular architectures. As a result of the above synthetic breakthrough, a variety of novel materials have been developed with versatile applications in very different fields such as biomedical and microelectronics.

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Rare earth metal initiated polymerizations of polar and nonpolar monomers to give high molecular weight polymers with extremely narrow molecular weight distribution

Cited by 97 publications

References 43 publications

Ring-opening polymerization of ?-caprolactone and ?-valerolactone using new Sm(III) ?-halo-bis(trimethylsilyl)amido complexes

Ring-opening polymerization of ?-caprolactone and ?-valerolactone using new Sm(III) ?-halo-bis(trimethylsilyl)amido complexes

The Organometallic Polymerization of (Meth)acrylates: An Overview

Novel Macromolecular Architectures Based on Aliphatic Polyesters: Relevance of the “Coordination-Insertion” Ring-Opening Polymerization

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