Growth of anisotropic single crystals of a random copolymer, poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] driven by cooperative –CH···O H-bonding

Liu, Changhao; Noda, Isao; Martin, David C.; Chase, D. Bruce; Ni, Chaoying; Rabolt, John F.

doi:10.1016/j.polymer.2018.08.046

Cited by 13 publications

(11 citation statements)

References 27 publications

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“…These interactions often lead to the formation of reactive radicals and molecular species, change in the ionic strength, or pH of the feed solution, thus altering the conditions of the experiments giving rise to skewed results. These effects have been discussed in great detail by Schneider et al, Woehl et al, , and Grogan et al For LPTEM of organic materials, it is particularly critical to carefully monitor and control the total electron dose used during imaging to limit the potential for structural damage of these beam-sensitive materials in addition to the liquid. , Beam sensitivity of organic crystalline solids can be obtained by measuring the doses required for the Bragg spots to fade away. ,, Previously published studies on TEM of PEDOT in the solid state have given an estimate of 60 e/A 2 for the total end point dose . It is also possible to get an estimate of the solid-state beam sensitivity of organic polymers from their melting points. , …”

Section: Introductionmentioning

confidence: 99%

“…47,48 Beam sensitivity of organic crystalline solids can be obtained by measuring the doses required for the Bragg spots to fade away. 8,49,50 Previously published studies on TEM of PEDOT in the solid state have given an estimate of 60 e/A 2 for the total end point dose. 1 It is also possible to get an estimate of the solid-state beam sensitivity of organic polymers from their melting points.…”

Section: ■ Introductionmentioning

confidence: 99%

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Direct Observation of Liquid-to-Solid Phase Transformations during the Electrochemical Deposition of Poly(3,4-ethylenedioxythiophene) (PEDOT) by Liquid-Phase Transmission Electron Microscopy (LPTEM)

Subramanian

Martin

2021

Macromolecules

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We have used liquid-phase transmission electron microscopy (LPTEM) to directly image the fundamental processes occurring at the electrode–solution interface during the electrochemical deposition of poly(3,4-ethylenedioxythiophene) (PEDOT) from an isotropic 3,4-ethylenedioxythiophene (EDOT) monomer solution. We clearly observed the various stages of the electrodeposition process including the initial nucleation of liquid-like EDOT oligomer droplets onto the glassy carbon working electrode and then merging, coalescence, and growth in size and thickness of these droplets into solid, stable, and dark PEDOT-conjugated polymer films. We also used correlative transmitted light optical microscopy to study this process, revealing the change in the color of the translucent clusters to the dark polymer film caused by the increase in conjugation length. From our studies, we have been able to correlate specific observations of local structure and dynamics to the liquid-like (EDOT oligomer) droplets and solid-like (PEDOT polymer) films including their mobility, mass thickness, edge roughness, size, circularity, and optical absorption.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Direct Observation of Liquid-to-Solid Phase Transformations during the Electrochemical Deposition of Poly(3,4-ethylenedioxythiophene) (PEDOT) by Liquid-Phase Transmission Electron Microscopy (LPTEM)

Subramanian

Martin

2021

Macromolecules

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“…Methylene iodide (MI) used for contact angle measurements was purchased from Sigma-Aldrich. All the as-received polymers were purified by a two-step standard purification method to remove polar and nonpolar impurities . Other chemicals were used as received.…”

Section: Methodsmentioning

confidence: 99%

“…All the as-received polymers were purified by a two-step standard purification method to remove polar and nonpolar impurities. 11 Other chemicals were used as received.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

“…Extensive studies have shown that both PHB and PHBHx exhibit intriguing crystallization profiles. Two crystal polymorphs have been identified so far: the alpha crystal form with an orthorhombic unit cell (space group: P 2 1 2 1 2 1 , a = 5.76 Å, b = 13.20 Å, and c = 5.96 Å) , and the beta form containing a planar zigzag chain conformation, typically found as a metastable ordered phase. − Formation of alpha crystals has been found to be driven by an unusually weak but cooperative H-bonding formed between the hydrogen of methyl group from one helix and the oxygen of carbonyl group from an adjacent helix in the crystal. − This unusual H-bonding network appears to enable the formation of a thermodynamically stable crystal structure even with the substantial presence of noncrystallizing comonomer units. The beta form has additional promising material properties and functionality, such as a higher tensile strength and significant piezoelectricity. − Thus, exploring technical methods to retard or inhibit the alpha crystallization of PHB has practical significance.…”

Section: Introductionmentioning

confidence: 99%

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Crystallization Retardation of Ultrathin Films of Poly[(R)-3-hydroxybutyrate] and a Random Copolymer Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] on an Aluminum Oxide Surface

et al. 2019

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Ultrathin films of biodegradable poly[(R)-3-hydroxybutyrate] (PHB) and its random copolymer poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (PHBHx) were prepared by spin-coating onto aluminum substrates with a naturally oxidized aluminum oxide (AO) surface layer or, alternatively, on gold substrates. The opposite surface of the film was in contact with ambient air. Isothermal crystallization kinetics of these films at room temperature were studied using infrared reflection absorption spectroscopy. The overall crystallization rate for all the polymers when crystallizing on AO is significantly retarded compared with the same polymer crystallizing on gold. It was found that the retardation effect was not due to a confinement effect. The crystallization retardation effect was especially enhanced for PHBHx with a higher (R)-3-hydroxyhexanoate content. Avrami analysis showed that the crystallization rate constant k (min–1) for all of the polymers on AO is approximately 3 to 4 orders of magnitude less than that found for the same polymer on gold. Grazing incident wide-angle X-ray diffraction showed that polymers on gold have both flat-on and edge-on crystallite orientations, whereas polymers on AO have a dominating edge-on crystallite orientation. Infrared studies on a quasi-monolayer film revealed no detectable H-bonding between PHB/PHBHx and the AO surface. The crystallization retardation mechanism was explained as being a sum of the dipole–dipole interactions of −CO of PHB or PHBHx and the −O–Al–O– groups of AO coupled with the rigid disordered amorphous nature of the AO surface.

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Study on poly(butylene adipate‐co‐terephthalate)/thermoplastic starch/poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate) biodegradable films with enhanced gas barrier properties

Wang,

Tian,

et al. 2024

Polymers for Advanced Techs

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Bioplastic films with excellent barrier properties were successfully prepared from poly(butylene adipate‐co‐terephthalate) (PBAT), thermoplastic starch (TPS), and poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate) (PHBHHx). The rheological, mechanical, barrier, dynamic mechanical properties, and microstructure of the PBAT/TPS/PHBHHx films were studied. The transition of the continuous phase in the blend significantly affects the properties of the films. The increase in PHBHHx content results in its transition from a dispersed phase to a continuous phase. This phase transition, along with the consequent increase in the crystallinity of PHBHHx, greatly enhances the barrier properties of the film. The percentage crystalline degree of PHBHHx increased from 10.9% to 25.1% with increasing PHBHHx content from 0% to 50%. The film containing 50% PHBHHx showed a significant decrease in both water vapor permeability (WVP) and oxygen permeability (OP) by 75.1% and 69.6%, respectively. It found that the film containing 50% PHBHHx exhibited a decrease of elongation at break from 505% to less than 10% but an unusual increase of tensile strength after a 72‐hour aging test, which is different from PBAT and PBAT/TPS films. However, this indicates that the extensibility of PHBHHx is more susceptible to the effects of aging test, leading to the rearrangement of polymer chains from disordered to ordered morphology.

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Growth of anisotropic single crystals of a random copolymer, poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] driven by cooperative –CH···O H-bonding

Cited by 13 publications

References 27 publications

Direct Observation of Liquid-to-Solid Phase Transformations during the Electrochemical Deposition of Poly(3,4-ethylenedioxythiophene) (PEDOT) by Liquid-Phase Transmission Electron Microscopy (LPTEM)

Direct Observation of Liquid-to-Solid Phase Transformations during the Electrochemical Deposition of Poly(3,4-ethylenedioxythiophene) (PEDOT) by Liquid-Phase Transmission Electron Microscopy (LPTEM)

Crystallization Retardation of Ultrathin Films of Poly[(R)-3-hydroxybutyrate] and a Random Copolymer Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] on an Aluminum Oxide Surface

Study on poly(butylene adipate‐co‐terephthalate)/thermoplastic starch/poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate) biodegradable films with enhanced gas barrier properties

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