Ring−Chain Interconversion in High-Performance Polymer Systems. 1. [Poly(oxy-4,4‘-biphenyleneoxy-1,4-phenylenesulfonyl-1,4-phenylene)] (Radel-R)

Colquhoun, Howard M.; Lewis, David F.; Hodge, Philip; Ben-Haida, Abderrazak; Williams, David J.; Baxter, Ian

doi:10.1021/ma020315u

Cited by 36 publications

(50 citation statements)

References 16 publications

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“…The ROMP of strained cyclic olefins is mainly enthalpy-driven.A relatively new type of ring-opening polymerization (ROP) exploits the well-known equilibria between cyclic oligomers and polymers [5][6][7][8][9][10] (Scheme 1). At high dilutions the equilibria lie heavily in favor of the cyclic oligomers, whereas at high concentrations they lie heavily in favor of the polymers.…”

mentioning

confidence: 99%

Entropically Driven Ring‐Opening‐Metathesis Polymerization of Macrocyclic Olefins with 21–84 Ring Atoms

Hodge¹,

Kamau²

2003

Angew Chem Int Ed

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The ring-opening-metathesis polymerization (ROMP) of strained cyclic olefins has been studied extensively, [1,2] especially since Grubbs' catalyst 1 [3] and the more recently introduced "second-generation" Grubbs' catalyst 2, [4] both of which are tolerant of many functional groups, became commercially available. The ROMP of strained cyclic olefins is mainly enthalpy-driven.A relatively new type of ring-opening polymerization (ROP) exploits the well-known equilibria between cyclic oligomers and polymers [5][6][7][8][9][10] (Scheme 1). At high dilutions the equilibria lie heavily in favor of the cyclic oligomers, whereas at high concentrations they lie heavily in favor of the polymers. Thus, if one or more cyclic oligomers are taken neat as starting materials, and equilibrium is established, polymer synthesis results. The cyclic oligomers used as the feedstock are generally not strained, so the enthalpy change on polymerization is minimal. This type of polymerization is, therefore, mainly entropically driven, and so the process can be abbreviated ED-ROP. As a neat mixture the cyclic oligomers have relatively little translational entropy and the rings occupy limited conformations; conformational flexibility increases greatly upon conversion into polymers. Since ED-ROP is an equilibration process the polydispersity of the polymer is expected to have a value of 2.0. ED-ROP has been investigated for various types of macrocyclic oligomers, [11,12] but not for macrocyclic olefins.Examples in which large, unstrained macrocycles (> 13 ring atoms) have been subjected to ROMP are rare, [2,[13][14][15] and there only appear to be two examples in which the polymer has been formed in high yield, isolated, and characterized. The first was the ROMP of the 14-membered cyclic ether 3 in the presence of the catalyst 1. This gave a polymer with M n 65 900 (M n = number-average molar mass).[2] The second example was the ROMP of ambrettolide, an unsaturated macrolide with 17 ring atoms.[13] A neat sample of this compound was polymerized in the presence of a catalyst prepared from tungsten hexachloride and tetramethyltin to give a polymer in 95 % yield with M n 95 000. Herein we show that when appropriate reaction conditions are used, unstrained macrocyclic olefins with up to 84, and possibly even more, ring atoms readily undergo entropically driven ROMP (ED-ROMP). Given that Grubbs and co-workers have recently reported an efficient method for the synthesis of very large macrocyclic olefins, [16] and that olefin-containing polymers are easily hydrogenated in the presence of decomposed metathesis catalysts, [17,18] ED-ROMP of large macrocyclic olefins is of more than theoretical interest.In the present work the monomers 4, 5, and 6, which have 21-, 28-, and 38-membered rings, respectively, were prepared by ring-closing metathesis (RCM). [2,[19][20][21] The monomer 4 had been synthesized previously by RCM in 70 % yield.[20] In a similar procedure, the a,w-diolefinic ester 7 and Grubbs' catalyst 1 (3 mol %) were slowly added over 24 h to ...

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confidence: 99%

Entropically Driven Ring‐Opening‐Metathesis Polymerization of Macrocyclic Olefins with 21–84 Ring Atoms

Hodge¹,

Kamau²

2003

Angew Chem Int Ed

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“…It is well known that the cyclic oligomers are formed in the low concentration polycondensation and intramolecular exchange reaction. [17][18][19] The cyclic trimers of poxycinnamoyl moiety were formed under low concentration. These cyclic oligomers have not high reactivity in this polymerization conditions without the catalysts.…”

Section: Control Of Nucleation Processmentioning

confidence: 99%

Fabrication of Poly(p-oxycinnamoyl) Nano-scale particles

et al. 2006

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Rigid-rod aromatic polymers are characterized by the unique combination of thermal and mechanical properties and they are generally developed as useful high -performance polymers for industrial applications. [1] Many publications point out some potential uses of these polymers when they are in particulate form.In particular, the spherical form is very useful and the addition of the powders of high-performance polymers in thermosetting resins to improve the fracture toughness has been investigated. [2][3][4][5][6][7][8] Recently, nano-scale polymer materials have been receiving much attention from the requirement of advanced new technology such as nanotechnology. [9] Although the nano-scale particles of rigid-rod aromatic polymers have a bright prospect of valuable industrial materials, they show usually neither solubility nor feasibility and this intractability makes them inaccessible to process by the conventional procedures. The nano-scale particles of the intractable aromatic polymers have not been fabricated so far.POC which is a wholly aromatic polyester possesses the antagonistic problem between properties and processability. In order to overcome this problem, studies carried out in our laboratory have been particularly focused on the morphology control of POC by using phase separation of oligomers during polymerization, and POC microspheres were successfully prepared by the polymerization of (E )-4-acetoxycinnamic acid (ACA) in liquid paraffin.[10] The POC microspheres were obtained via the formation of microdroplets by liquid-liquid phaseseparation and the subsequent further polymerization in them. The POC microspheres are formed by the nucleation and growth mechanism. This preparation procedure stipulated a useful method for fabrication of intractable polymer microspheres. Diameter control of the microspheres was of great importance in industrial applications and the method to control diameter of the POC microspheres was developed by the depression of the coalescence of the microdroplets, which was the growth-control method.[11] This method could control the diameter of POC spheres, but the control range was from 1 to 5 µm. The nano-scale particles could not be fabricated only by this growth-control method, and the nucleation-control method should be developed.This article examines the influence of the polymerization temperature on the diameter of the POC spheres and describes the fabrication of the POC nanoscale particles by self-seeding polymerization of ACA.Abstract : Fabrication of poly(p-oxycinnamoyl) (POC) nano-scale particles was examined by using self-seeding polymerization of (E )-4-acetoxycinnamic acid in liquid paraffin. The diameter of the POC spheres was very susceptible to the polymerization temperature and the temperature drop was very efficient to control the nucleation process by the adjustment of the degree of super saturation leading to the decrease in the diameter. The average diameter of the spheres prepared at 320 was 3.6 µm, whereas, the temperature drop from 320 to 250 just befor...

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“…[12] The MCOs 5 were isolated and characterized as described previously. [12] The composition (wt.-%) of the product as determined by gel permeation chromatography (GPC) was: cyclic dimer, 12%; cyclic trimer, 20%; cyclic tetramer, 15%; cyclic pentamer, 13%; cyclic hexamer, 12%; cyclic heptamer, 8%; and higher homologues 20%. The matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) results showed peaks from the cyclic dimer up to the cyclic pentadecamer.…”

Section: Experimental Partmentioning

confidence: 99%

“…In initial experiments, polymerizations were carried out at 320 8C for 10 min, catalyzed by 3.5 mol-% of the caesium salt 6 of 4-benzoylthiophenol. [12] In a second set of experiments the reaction temperature was raised from 310 to 330 8C and the reaction time was extended from 10 to 35 min. The catalyst was also replaced by 3.5 mol-% of the caesium salt of 4-hydroxybenzophenone 7.…”

Section: Ring-opening Polymerizationsmentioning

confidence: 99%

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A Novel Approach to Processing High‐Performance Polymers that Exploits Entropically Driven Ring‐Opening Polymerization

Ben-Haida

Colquhoun

Hodge

et al. 2005

Macromol. Rapid Commun.

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Summary: Blends of the poly(ether sulfone) derived from 4,4′‐biphenol and 4,4′‐dichlorodiphenylsulfone (Radel‐R™) with its homologous macrocyclic oligomers show greatly lowered melt viscosities relative to that of the parent polymer, potentially enabling more facile production and fabrication of fiber‐reinforced composite materials. The macrocycles can then undergo entropically driven ring‐opening polymerization in situ. The required blends can be obtained easily in one step, by carrying out polycondensations at concentrations lower than those usually used for polymer synthesis.Percentage of MCOs 5 in the product as a function of total monomer concentration.imagePercentage of MCOs 5 in the product as a function of total monomer concentration.

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Ring−Chain Interconversion in High-Performance Polymer Systems. 1. [Poly(oxy-4,4‘-biphenyleneoxy-1,4-phenylenesulfonyl-1,4-phenylene)] (Radel-R)

Cited by 36 publications

References 16 publications

Entropically Driven Ring‐Opening‐Metathesis Polymerization of Macrocyclic Olefins with 21–84 Ring Atoms

Entropically Driven Ring‐Opening‐Metathesis Polymerization of Macrocyclic Olefins with 21–84 Ring Atoms

Fabrication of Poly(p-oxycinnamoyl) Nano-scale particles

A Novel Approach to Processing High‐Performance Polymers that Exploits Entropically Driven Ring‐Opening Polymerization

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