Synthesis of the First Organic Polymer/Polyphosphazene Block Copolymers:  Ambient Temperature Synthesis of Triblock Poly(Phosphazene−ethylene oxide) Copolymers

Nelson, James M.; Primrose, A. Paul; Hartle, Thomas J.; Allcock, Harry R.; Manners, Ian

doi:10.1021/ma9716995

Cited by 68 publications

(70 citation statements)

References 20 publications

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“…8 Therefore, the formation of diblock copolymers during the synthesis of polyphosphazenes from [NPCl 2 ] n in THF as solvent cannot be ruled out. Similar sequential polymerizations leading to different types of diblock copolymers involving THF have been described, 9 and poly(phosphazene ethylene oxide) block copolymers have been recently prepared, 10 although by condensation re-actions. Therefore, we also considered it to be of interest to study the origin of the PTHF present in 1.…”

Section: Introductionmentioning

confidence: 99%

On the presence of polytetrahydrofuran in the polyspiro-phosphazenes [NP(O2C12H8)]n prepared from [NPCl2]n and 2,2?-dihydroxybiphenyl in THF as solvent

Carriedo

Alonso

Elipe

et al. 2000

J. Appl. Polym. Sci.

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Polydichlorophosphazene [NPCl 2 ] n reacts with the diphenol 2,2Ј-(HO)C 6 H 4 -C 6 H 4 (OH) in THF in the presence of K 2 CO 3 to give the polymers [NP(O 2 C 12 H 8 ) ⅐ x(OC 4 H 8 )] n (1) that contain variable ammouts of polytetrahydrofuran (PTHF) with x ranging from 0.05 to 0.8. This PTHF content (x) depends on the method followed to prepare the THF solutions of [NPCl 2 ] n used for the reactions with the biphenol and can be made negligibly small, forming these solutions in the presence of K 2 CO 3 . This reveals the presence in the [NPCl 2 ] n of acidic species capable of catalyzing the ring opening polymerization of THF. Polyphosphazene [NP(O 2 C 12 H 8 )] n (2) was prepared completely free of PTHF using dioxane as solvent. A comparison of the thermal behavior and morphological data of the polymers 1, 2, PTHF (5), and mixtures of [NP(O 2 C 12 H 8 )] n ϩ x(OC 4 H 8 ) m (4) revealed that the products 1 are strongly interacting polymer blends and ruled out the possibility of block copolymers.

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Section: Introductionmentioning

confidence: 99%

On the presence of polytetrahydrofuran in the polyspiro-phosphazenes [NP(O2C12H8)]n prepared from [NPCl2]n and 2,2?-dihydroxybiphenyl in THF as solvent

Carriedo

Alonso

Elipe

et al. 2000

J. Appl. Polym. Sci.

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“…This can limit the utility of these materials in nanoscale lithography because the etch selectivity between the blocks, and their etch resistance for subsequent pattern transfer steps, is typically low. It is therefore interesting to examine thin film triblock terpolymers in which one of the blocks contains inorganic components which impart high etch selectivity and etch resistance.Triblock copolymers containing inorganic blocks such as polyphosphazenes, [19,20] polysilanes [21,22] and polysulfides [23] have been prepared previously. However, these are symmetrical ABA type triblock copolymers, which phase separate on the nanoscale into morphologies comparable to diblock copolymers.…”

mentioning

confidence: 99%

Self‐Assembled Nanoscale Ring Arrays from a Polystyrene‐b‐polyferrocenylsilane‐b‐poly(2‐vinylpyridine)Triblock Terpolymer Thin Film

et al. 2009

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Block copolymers can microphase-separate into periodic nanoscale structures with well-defined geometries and length scales, making them attractive materials for self-assembled nanolithography. [1][2][3][4] Ordered arrays of block copolymer spheres, cylinders, or lamellae have been used to pattern features in functional materials with sizes of $10-50 nm. The fabrication of a range of devices, such as silicon capacitors and transistors, discrete magnetic storage media, and photonic crystals, [5][6][7][8] have been demonstrated using block copolymer lithography.Previous work has mainly focused on diblock copolymers, with the study of triblock or multiblock copolymers being less actively pursued, largely due to the increased level of synthetic difficulty. However, these materials offer a wider range of geometries than the line and dot patterns available from diblock copolymers, making them potentially valuable for nanolithography applications. In particular, triblock terpolymers can form ring shaped features, which are useful in the fabrication of memories or sensors, [9][10][11] and quantum devices. [12][13][14] Ring-shaped structures have been formed previously from thin films of core/shell structured linear ABC triblock terpolymers, [15][16][17] in which the cylinders are oriented perpendicular to the film plane during the anneal process. However, this work, as well as work on thin film triblock terpolymers of other morphologies, [18] has focused on materials in which all three blocks consist of organic segments. This can limit the utility of these materials in nanoscale lithography because the etch selectivity between the blocks, and their etch resistance for subsequent pattern transfer steps, is typically low. It is therefore interesting to examine thin film triblock terpolymers in which one of the blocks contains inorganic components which impart high etch selectivity and etch resistance.Triblock copolymers containing inorganic blocks such as polyphosphazenes, [19,20] polysilanes [21,22] and polysulfides [23] have been prepared previously. However, these are symmetrical ABA type triblock copolymers, which phase separate on the nanoscale into morphologies comparable to diblock copolymers.There have been several studies on bulk ABC triblock terpolymers with an inorganic polydimethylsiloxane (PDMS) block, [24][25][26] such as polyisoprene-b-polystyrene-b-poly(dimethyl siloxane) [24,25] and poly(ethyleneoxide)-b-poly(dimethyl siloxane)-b-poly(methyl oxazoline). [26] Polyferrocenylsilane (PFS) is a metal-containing polymer with iron and silicon in the polymer backbone.[27] Synthesis of PFS with controlled molecular weights and narrow polydispersities is achieved by a living anionic mechanism. [28,29] PFS has also been incorporated into multiblock copolymers with a variety of organic and inorganic coblocks. [28][29][30][31][32][33][34] These block copolymers microphase-separate to give ordered arrays of iron and silicon containing nanostructures, which have already been used in lithographic applications. [35][36][37]...

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“…An alternative to the ring opening polymerization of 2 used in most reactions is the condensation polymerization of a chloro‐phosphoranimine, as shown in Fig. . In this process, a catalytic amount or PCl 5 or a related Lewis acid brings about the formation of linear poly(dichlorophosphazene).…”

Section: Poly(dichlorophosphazene) By the Living Cationic Polymerizatmentioning

confidence: 99%

Generation of structural diversity in polyphosphazenes

Allcock

2013

Applied Organom Chemis

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Polyphosphazenes are macromolecules with a chain of alternating phosphorus and nitrogen atoms and with two (usually) organic side groups linked to each phosphorus. Although the earliest poly(organophosphazenes) were essentially linear polymers each bearing only one type of side group along the chain, research in our program in recent years has widened the scope to include mixed‐substituent polymers with two or more different side groups, block copolymers, comb structures, stars, and dendrimers, all with a wide variety of different properties. In addition, supramolecular systems have also been synthesized including vesicles, microspheres, and a variety of composite systems. This review provides a summary of these developments together with an introduction to the widening array of developing uses. Copyright © 2013 John Wiley & Sons, Ltd.

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Synthesis of the First Organic Polymer/Polyphosphazene Block Copolymers: Ambient Temperature Synthesis of Triblock Poly(Phosphazene−ethylene oxide) Copolymers

Cited by 68 publications

References 20 publications

On the presence of polytetrahydrofuran in the polyspiro-phosphazenes [NP(O2C12H8)]n prepared from [NPCl2]n and 2,2?-dihydroxybiphenyl in THF as solvent

On the presence of polytetrahydrofuran in the polyspiro-phosphazenes [NP(O2C12H8)]n prepared from [NPCl2]n and 2,2?-dihydroxybiphenyl in THF as solvent

Self‐Assembled Nanoscale Ring Arrays from a Polystyrene‐b‐polyferrocenylsilane‐b‐poly(2‐vinylpyridine)Triblock Terpolymer Thin Film

Generation of structural diversity in polyphosphazenes

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