Conformational Characteristics and Configurational Properties of Poly(ethylene oxide-<i>alt</i>-ethylene sulfide)

Sasanuma, Yuji; Asai, Shiho; Kumagai, Ryota

doi:10.1021/ma070065n

Cited by 23 publications

(40 citation statements)

References 35 publications

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“…In accordance with the stereo- and regiosequences of the PPC chains thus generated, the super generator matrices H β α ’s (α = R or S and β = O or A ) 23 were chosen, arranged, and multiplied sequentially to yield the configurational properties and thermodynamic quantities for the individual chains. The final outcomes were the averages over all of the n c chains.…”

Section: Methodsmentioning

confidence: 99%

Structure–Property Relationships of Poly(ethylene carbonate) and Poly(propylene carbonate)

Sasanuma

Takahashi

2017

ACS Omega

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Conformational characteristics of poly(ethylene carbonate) (PEC) and poly(propylene carbonate) (PPC) have been revealed via molecular orbital (MO) calculations and nuclear magnetic resonance (NMR) experiments on model compounds with the same bond sequences as those of the polycarbonates. Bond conformations derived from the MO calculations on the models were in exact agreement with those from the NMR experiments. Both PEC and PPC were indicated to adopt distorted conformations including a number of gauche bonds and cover themselves with negative charges, thus failing to form a regular packing and remaining amorphous. The MO data were applied to the refined rotational isomeric state (RIS) calculations to yield configurational properties such as the characteristic ratio, its temperature coefficient, the configurational entropy, and average geometrical parameters of unperturbed PEC and PPC chains. In the RIS calculations on PPC, the regio- and stereosequences were generated according to the Bernoulli trial or Markov stochastic process. In consequence, it was shown that the configurational properties of PPC do not depend significantly on its regio- and stereoregularities. The internal energy contribution to rubberlike chain elasticity, calculated from the temperature coefficient of the characteristic ratio, has indicated the possibility that PEC and PPC will behave as elastomers. The practical applications and potential utilizations of the polycarbonates are discussed on the basis of the conformational characteristics and configurational properties.

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Section: Methodsmentioning

confidence: 99%

Structure–Property Relationships of Poly(ethylene carbonate) and Poly(propylene carbonate)

Sasanuma

Takahashi

2017

ACS Omega

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“…To distinguish between the viscosity and SLS data, we will hereafter suffix the former and latter with (Z) and (l), respectively. The expansion factor a 2 S was calculated with equation (9) and (10) from b(Z) (159Â 10 À24 cm 3 ) and [oS 2 4 0 /M w ](Z) (1.05Â 10 À17 cm 2 ) and used to evaluate or 2 4 0 (l) according to o r 2 Crystal structure of PHB The crystal structure of PHB has been determined by, for example, Cornibert and Marchessault, 38 Yokouchi et al 39 and Brüchner et al 40 According to Yokouchi et al, the PHB chains are packed in an orthorhombic cell of P2 1 2 1 2 1 À D 4 2 with a ¼ 5.76 Å , b ¼ 13.20 Å , and c (fiber axis) ¼ 5.96 Å , and two molecular chains are pass through the unit cell as shown in Figure 6. The PHB chain forms a left-handed 2 1 helix of the most stable ttg þ g þ conformation ( Table 3).…”

Section: Solution Properties Of Phbmentioning

confidence: 99%

Elucidation of conformational characteristics and configurational properties of poly((R)-3-hydroxybutyrate) by ab initio statistical mechanics

Sasanuma

Katsumata

2012

Polym J

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Conformational free energies and geometrical parameters derived from ab initio molecular orbital (MO) calculations for monomeric and dimeric model compounds of poly((R)-3-hydroxybutyrate) (PHB) were introduced into the refined rotational isomeric state (RIS) scheme to yield the characteristic ratio, configurational entropy, configurational internal energy, bond conformations and averaged geometrical parameters of PHB. The reliability of the MO calculations was confirmed through comparison with 1 H and 13 C nuclear magnetic resonance experiments for the monomeric model compound. The characteristic ratio (5.60) derived from the refined RIS calculations for the unperturbed PHB chain at 25 1C is in satisfactory agreement with the experimental values (6.1-6.3). The crystalline PHB chain is known to adopt the ttg þ g þ conformation in the repeating unit. A previous study revealed that a trimeric (R)-3-hydroxybutyrate substrate bound on a PHB depolymerase lies in the ttg þ g þ and tg À tt conformations. In our MO calculations, the former conformation is the most stable, and the latter is metastable but further stabilized by intermolecular C ¼ O?H ÀN and C ¼ O?H ÀO hydrogen bonds on the enzyme.

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“…On the basis of the reliable MO calculations thus established, we have investigated the conformational characteristics and intramolecular interactions of the two FUs, and evaluated the congurational properties of the two polymers by the rened RIS scheme. 15 This article reports the processes and results in detail and discusses the differences between PEA and PU, especially in terms of chain elasticity and biodegradability.…”

Section: Introductionmentioning

confidence: 99%

Computational design of polymers: poly(ester amide) and polyurethane

2017

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Conformational Characteristics and Configurational Properties of Poly(ethylene oxide-alt-ethylene sulfide)

Cited by 23 publications

References 35 publications

Structure–Property Relationships of Poly(ethylene carbonate) and Poly(propylene carbonate)

Structure–Property Relationships of Poly(ethylene carbonate) and Poly(propylene carbonate)

Elucidation of conformational characteristics and configurational properties of poly((R)-3-hydroxybutyrate) by ab initio statistical mechanics

Computational design of polymers: poly(ester amide) and polyurethane

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