Mechanistic study on Sn(Oct)2-catalyzed, ring-opening polymerization of p-dioxanone by surface-initiated polymerization and x-ray photoelectron spectroscopy

2005 ◽  
Vol 11 (4) ◽  
pp. 265-268 ◽  
Author(s):  
Kuk Ro Yoon ◽  
Yongseong Kim ◽  
Insung S. Choi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Mechanistic Study ◽  
X Ray ◽  
Surface Initiated Polymerization

The synthesis and polymerization behaviour of silicon-bridged [1]- and [2]ferrocenophanes with sterically demanding trimethylsilyl substituents attached to the cyclopentadienyl rings

1995 ◽  
Vol 73 (11) ◽  
pp. 2069-2078 ◽  
Author(s):  
Timothy J. Peckham ◽  
Daniel A. Foucher ◽  
Alan J. Lough ◽  
Ian Manners
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Monoclinic Space Group ◽  
Organometallic Polymers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cyclopentadienyl Ligands ◽  
Sterically Demanding ◽  
High Molecular Weight Poly

The silicon-bridged [1]ferrocenophane Fe(η-C5H3SiMe3)2(SiMe2) (5) was synthesized via the reaction of Li2[Fe(η-C5H3SiMe3)2]•tmeda (tmeda = tetramethylethylenediamine) with Me2SiCl2 in hexanes. The disilane-bridged [2]ferrocenophane Fe(η-C5H3SiMe3)2(Si2Me4) (7) was prepared using a similar route from the disilane ClMe2SiSiMe2Cl. Despite the presence of sterically demanding SiMe3 substituents on the cyclopentadienyl rings, compound 5 was found to undergo thermal ring-opening polymerization at 170 °C to produce very soluble, high molecular weight poly(ferrocenylsilane) 6 with Mw = 1.4 × 105, Mn = 8.4 × 104. However, the [2]ferrocenophane 7 was found to be resistant to thermal ring-opening polymerization even at 350 °C and decomposed above 380 °C. A single-crystal X-ray diffraction study of 7 revealed that the steric interactions between the bulky SiMe3 groups are relieved by a significant twisting of the disilane bridge with respect to the plane defined by the centroids of the cyclopentadienyl ligands and the metal atom. The angle between the planes of the cyclopentadienyl rings in 7 was found to be 5.4(6)°, slightly greater than that in the non-silylated analogue Fe(η-C5H4)2(Si2Me4) (4a) (4.19(2)°), and dramatically less than the corresponding tilt angle of the strained, polymerizable, silicon-bridged [1]ferrocenophane Fe(η-C5H4)2(SiMe2) (1) (20.8(5)°). The length of the Si—Si bond in 7 (2.342(3) Å) was found to be close to the sum of the covalent radii (2.34 Å). Crystals of 7 are monoclinic, space group C2/c, with a = 23.689(3) Å, b = 11.174(1) Å, c = 31.027(3) Å, β = 109.16(1)°, V = 7758(2) Å3, and Z = 12. Keywords: ring-opening polymerization, ferrocenophane, organometallic polymers.

Synthesis, Characterization and Optical Properties of PLA / P3HT Blends Thin Films

2021 ◽  
Vol 19 (5) ◽  
pp. 132-138
Author(s):  
Maan Abd-Alameer Salih ◽  
Q.S. Kareem ◽  
Mohammed Hadi Shinen
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Ring Opening ◽  
Energy Gap ◽  
Ring Opening Polymerization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conductivity Increase ◽  
Ft Ir

In this exploration Poly lactic corrosive (PLA) was orchestrated the ring-opening polymerization Poly lactic corrosive (PLA) blended with poly(3-hexylthiophene) (P3HT) which prepared by solution. Blends thin films Synthesis by spin coating technique and using Tetrahydrofuran (THF) as solvent. PLA powder was 'characterized by' 'X-ray' 'diffraction', '(FT-IR)'. pure Optical properties (PLA), (PLA)/P3HT blends thin films with different percentage of P3HT (0, 1, 2, and 3) wt% were investigated using UV-VS spectroscopy The results showed that the absorption, absorption coefficient, extinction coefficient and conductivity increase with increasing the rate of deformation P3HT, The energy gap decreases with increasing deformation.

Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

Synthesis of Self-Assembled Metal-Oxide Nanostructures in a Diblock Copolymer Matrix and Integration onto Semiconductor Surfaces

2000 ◽  
Vol 642 ◽  
Author(s):  
Robert F. Mulligan ◽  
Agis A. Iliadis ◽  
U. Lee ◽  
Peter Kofinas
Keyword(s):  
Block Copolymer ◽  
Diblock Copolymer ◽  
Photoelectron Spectroscopy ◽  
Ring Opening ◽  
Diblock Copolymers ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Metal Oxide Nanostructures ◽  
Self Assembled ◽  
Zno Nanoclusters

ABSTRACTThe synthesis of self-assembled ZnO nanostructures at room temperature using a microphase separated diblock copolymer as a template is reported. Poly(norbornene) / poly(norbornene-dicarboxylic acid) diblock copolymers were synthesized using Ring Opening Metathesis Polymerization (ROMP). The polymers were dissolved and the solutions were doped with ZnCl2. Films were formed from this solution, and subsequently reacted with NH4OH. This converted the ZnCl2 into ZnO contained within the microphase-separated nanodomains of the block copolymer. Fourier Transform Infrared Spectroscopy verified the association of the metal to the second block of the polymer, and X-ray Photoelectron Spectroscopy verified the conversion of the salt to ZnO nanoclusters. The development of such ZnO - block copolymer nanocomposites is targeting the functionalization of nanostructures into device technologies.

Synthesis and X-ray Structures of New Titanium(IV) Aryloxides and Their Exploitation for the Ring Opening Polymerization of ε-Caprolactone

2006 ◽  
Vol 45 (5) ◽  
pp. 2282-2287 ◽  
Author(s):  
Matthew G. Davidson ◽  
Matthew D. Jones ◽  
Matthew D. Lunn ◽  
Mary F. Mahon
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
X Ray

scholarly journals Yttrium and Lithium Keto-β-Diketiminate Complexes [{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]2Y(μ2-Cl)2Li(THF)2 and {[{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]Li(THF)}n. Synthesis, Molecular Structures, and Catalytic Activity in ε-Caprolactone Polymerization

2021 ◽  
Vol 47 (2) ◽  
pp. 144-154
Author(s):  
G. G. Skvortsov ◽  
A. V. Cherkasov ◽  
D. L. Vorozhtsov ◽  
E. S. Shchegravina ◽  
A. A. Trifonov
Keyword(s):  
Catalytic Activity ◽  
Diffraction Analysis ◽  
Exchange Reaction ◽  
Ring Opening ◽  
Crystalline State ◽  
Ring Opening Polymerization ◽  
Molecular Structures ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray

Abstract The reaction of lithium β-diketiminate [{2,6-Me2C6H3N=CMe}2CH]Li with benzophenone in toluene at 25°C affords the coordination complex [{2,6-Me2C6H3N=CMe}2CH]Li(Ph2C=O) (I). New keto-β-diketimine {2,6-Me2C6H3N=C(Me)}2CHC(tert-Bu)=O (II) is synthesized by the reaction of tert-Bu(C=O)Cl with [{2,6-Me2C6H3N=CMe}2CH]Li. The metallation of keto-β-diketimine II with n-butyllithium in THF at 0°C gives lithium keto-β-diketiminate {[{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]Li(THF)}n (III). The exchange reaction of YCl3 with compound III (molar ratio 1 : 2, THF) affords the yttrium bis(keto-diketiminate) complex [{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]2Y(μ2-Cl)2L-(THF)2 (IV). The molecular structures of complexes I, III, and IV are determined by X-ray diffraction analysis (CIF files CCDC nos. 2001131 (I), 2001132 (III), and 2001133 (IV)). Complex IV in the crystalline state exists as an ate complex with one LiCl molecule. Complexes I, III, and IV are catalysts of ring-opening polymerization of ε-caprolactone in toluene at 25°С.

scholarly journals Aminated Graphene-Graft-Oligo(Glutamic Acid) /Poly(ε-Caprolactone) Composites: Preparation, Characterization and Biological Evaluation

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2628
Author(s):  
Mariia Stepanova ◽  
Olga Solomakha ◽  
Maxim Rabchinskii ◽  
Ilia Averianov ◽  
Iosif Gofman ◽  
...  
Keyword(s):  
Composite Materials ◽  
Glutamic Acid ◽  
Polymer Matrix ◽  
Photoelectron Spectroscopy ◽  
Ring Opening ◽  
Soft Tissues ◽  
Biological Properties ◽  
Biological Evaluation ◽  
Benzyl Ester ◽  
X Ray

Biodegradable and biocompatible composites are of great interest as biomedical materials for various regeneration processes such as the regeneration of bones, cartilage and soft tissues. Modification of the filler surface can improve its compatibility with the polymer matrix, and, as a result, the characteristics and properties of composite materials. This work is devoted to the synthesis and modification of aminated graphene with oligomers of glutamic acid and their use for the preparation of composite materials based on poly(ε-caprolactone). Ring-opening polymerization of N-carboxyanhydride of glutamic acid γ-benzyl ester was used to graft oligomers of glutamic acid from the surface of aminated graphene. The success of the modification was confirmed by Fourier-transform infrared and X-ray photoelectron spectroscopy as well as thermogravimetric analysis. In addition, the dispersions of neat and modified aminated graphene were analyzed by dynamic and electrophoretic light scattering to monitor changes in the characteristics due to modification. The poly(ε-caprolactone) films filled with neat and modified aminated graphene were manufactured and carefully characterized for their mechanical and biological properties. Grafting of glutamic acid oligomers from the surface of aminated graphene improved the distribution of the filler in the polymer matrix that, in turn, positively affected the mechanical properties of composite materials in comparison to ones containing the unmodified filler. Moreover, the modification improved the biocompatibility of the filler with human MG-63 osteoblast-like cells.

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