Investigation of the stereoregularity of poly(vinyl alcohol)

Fujii, Kiyoshi; Mochizuki, Takani; Imoto, Saburo; Ukida, Junji; Matsumoto, Masakazu

doi:10.1002/pol.1964.100020523

Cited by 27 publications

(6 citation statements)

References 35 publications

(2 reference statements)

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“…Other IR adsorption bands appeared at ∼916 and 850 cm -1 and are assigned to the δ (CH 2 ) and ν (CC) , respectively. The rr-triad sequence shows an IR adsorption at 916 cm -1 , whereas the mm-triad sequence does not, and the ratio of these bands ( D 916 / D 850 ) reflects the syndiotacticity of the PVA . In this system, the short-chain PVA shows an IR adsorption at 916 cm -1 ; however, the change in the D 916 / D 850 with the blending of lignin is not significant.…”

Section: Resultsmentioning

confidence: 81%

The Formation of Strong Intermolecular Interactions in Immiscible Blends of Poly(vinyl alcohol) (PVA) and Lignin

2003

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The intermolecular interactions of lignin with a hydrophilic polymer, poly(vinyl alcohol) (PVA), were studied using thermal analyses and FT-IR spectroscopy of a series of PVA/hardwood kraft lignin blend fibers prepared by thermal extrusion. Although two phases are observed in this blend system, some of the lignin was closely associated with the PVA in the PVA-rich phase. The crystallinity of the PVA fraction was reduced with increasing lignin content. An interaction energy density of -9.34 cal cm(-1), calculated from melting point depression data, suggests that strong intermolecular interactions exist between PVA and lignin. FT-IR analysis indicates the formation of strong intermolecular hydrogen bonds between the hydroxyl groups of PVA and lignin. Although the PVA/lignin blend system is immiscible in the bulk, the results herein show the existence of some specific intermolecular interaction between PVA and lignin.

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Section: Resultsmentioning

confidence: 81%

The Formation of Strong Intermolecular Interactions in Immiscible Blends of Poly(vinyl alcohol) (PVA) and Lignin

2003

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“…X-ray diffraction patterns of PVA, P3TESNa, P3TESH, and the blends of P3TESNa/ PVA and P3TESH/PVA both with a 1/1 ratio of repeat units are shown in Figure 1; their characteristic angles at intensity maxima and corresponding values of d spacing calculated using the Bragg's law are listed in Table 2. For PVA, a broad diffused scattering peak ranging from 2θ ) 9 to 28°with a moderate intensity peak at 2θ ) 19.5°(d ) 4.6 Å) is observed, indicating the coexistence of disorder and crystalline phases 19 in the bulk polymer. The X-ray diffraction patterns of P3TESNa and P3TESH are nearly the same; each has a peak with moderate intensity centered at 2θ ) 22.5°( d ) 4.0 Å) and a broad peak centered at 2θ ) 16°(d ) 5.5 Å).…”

Section: Gel Permeation Chromatography (Gpc) Resultsmentioning

confidence: 98%

Compatibilities and Electrostatic Interactions in the Blends of Self-Acid-Doped Conjugated Conducting Polymer, Poly[2-(3‘-thienyl)ethanesulfonic acid], and Its Sodium Salt with Poly(vinyl alcohol)

Chen

Mei

1996

Macromolecules

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The structure and properties of the blends poly[sodium 2-(3‘-thienyl)ethanesulfonate] (P3TESNa)/poly(vinyl alcohol) (PVA) and poly[2-(3‘-thienyl)ethanesulfonic acid] (P3TESH)/PVA, both with a mole ratio 1/1 of the two components, were investigated by gel permeation chromatography (GPC), X-ray diffraction (XRD), infrared spectroscopy (IR), ultraviolet−visible−near-infrared spectroscopy (UV−vis−near-IR), X-ray photoelectron spectroscopy (XPS), dynamic mechanical analysis (DMA), and conductivity. The blends were cast from water solutions of the two components. The P3TESH/PVA blend consists of the two phases, a P3TESH phase and a P3TESH/PVA complex phase, in which no characteristic of the PVA component is observed. In the complex phase, the two polymers are intimately mixed. However, this compatibility is different from that of conventional polymer blends in that the present blend has an additional phase composed of one of the two pure components. The phase with the complexes has glass transition and side chain relaxation temperatures higher than that of the pure components, and has new chain packing as reflected in a new X-ray diffraction peak (2θ) at 21.5°. This type of compatibility results from the hydrogen-bonding (or electrostatic) interaction between the two components and the strong aggregation of one component (in this case, P3TESH). The blending of P3TESH with PVA leads to a significant undoping, and the conductivity decreases from 10-2 S/cm in the pure state to 10-6 S/cm. The P3TESH subchains that are not self-acid-doped (or containing the −SO3H group) exhibit a red shift of the UV−vis absorption maximum by 44 nm, resulting from an increase in coplanarity caused by a repulsion between neighboring −SO3− groups. For the P3TESNa/PVA blend, the phase structure and electrostatic interaction are similar to those in the above blend. A drastic red shift of the UV−vis absorption maximum by 76 nm (0.52 eV) accompanied by a color change from pale orange-yellow to bright orange-red after the blending is observed. The red shift results from the strong electrostatic interaction between the Na+ ion of P3TESNa and the O atom of PVA. Such a large red shift is equivalent to the thermochromism and solvatochromism of poly(3-alkylthiophene)s. The conductivity of P3TESNa (10-7 S/cm) drops by 1 order of magnitude after blending with PVA, but the blend can be doped by a protonic acid to give a conductivity of 10-3 S/cm.

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“…The Roedel mechanism thus appears to be entirely vindicated. It is perhaps somewhat surprising that the 1,5 transfer Of hydrogen, even though favored by the formation of a quasi-six-membered ring as a transition state, appears to be exclusively preferred over a possible 1,4 transfer (producing a propyl branch), which evidently can occur in the reaction of (8) . I. Roedel, J. Amer.…”

Section: Discussionmentioning

confidence: 99%

Carbon-13 Observations of the Nature of the Short-Chain Branches in Low-Density Polyethylene

Dorman¹,

Otocka²,

Bovey³

1972

Macromolecules

105

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The UC nmr spectra of low-density polyethylenes are compared to those of model copolymers and to calculated spectra based on model hydrocarbons. It is unequivocally demonstrated that the short branches are «-butyl, thus confirming the Roedel "backbiting" hypothesis.It is well known that the morphology and solid-state properties of polyethylene are critically dependent on the frequency of short-chain branches. It seems highly probable that they are also influenced to some degree by the length of these branches, as well as the trior tetrafunctional character of the branch points. There appears to have grown up during the past decade a presumption that the short-chain branch length is known and is no longer subject to question. This is borne out by the virtual absence of any current or recent studies of this problem. Nevertheless, a critical examination of the literature shows that the accepted conclusions, largely drawn from infrared and irradiation measurements, are ambiguous. Even where clear answers seem to have been provided, it is highly probable, as we shall show in this paper, that they are at least qualitatively in error.Carbon-13 Nmr Spectra of Saturated Hydrocarbons Carbon-13 magnetic resonance spectroscopy (cmr) promises to be extremely useful in the elucidation of alkane and large alkyl structures. This is due not only to the large range of chemical shifts (ca. 40 ppm) in which saturated carbons are found to occur, but also to the simple empirically derived relationships which allow the prediction of the chemical shift of any carbon for which the local structure is known.1-3 In general, it is found that carbons at or near a branch point are the least shielded in such structures, while methyl resonances are most frequently found at highest field. These conclusions suggest that 13C chemical shifts of polyethylenes should provide new information regarding the structure and extent of

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Investigation of the stereoregularity of poly(vinyl alcohol)

Cited by 27 publications

References 35 publications

The Formation of Strong Intermolecular Interactions in Immiscible Blends of Poly(vinyl alcohol) (PVA) and Lignin

The Formation of Strong Intermolecular Interactions in Immiscible Blends of Poly(vinyl alcohol) (PVA) and Lignin

Compatibilities and Electrostatic Interactions in the Blends of Self-Acid-Doped Conjugated Conducting Polymer, Poly[2-(3‘-thienyl)ethanesulfonic acid], and Its Sodium Salt with Poly(vinyl alcohol)

Carbon-13 Observations of the Nature of the Short-Chain Branches in Low-Density Polyethylene

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