Infrared investigations of the polymorphic modifications of polybutene‐1

Goldbach, G.; Peitscher, G.

doi:10.1002/pol.1968.110061105

Cited by 71 publications

(39 citation statements)

References 7 publications

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“…[3] This transformation takes place during days or weeks at room temperature and much faster when applying stress deformation. The untwined hexagonal form (Form I, 3 1 helix) results when the polymer crystallizes from solution [4,5] or from the melt under high pressure a . [6] The orthorhombic form, or Form III (4 1 helix), has been obtained only from solutions.…”

Section: Introductionmentioning

confidence: 99%

Crystallization and Transformation of Polybutene‐1

Kaszonyiova

Rybnikář

Geil

2004

Journal of Macromolecular Science, Part B

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The isothermal crystallization and phase II ! I transformation of bulk polybutene-1 at various temperatures have been characterized by x-ray diffraction. The crystallization rate can be increased or decreased by the addition of various solids, with sodium salicylate and talc, e.g., increasing the rate by .100% and, unexpectedly, decreasing the rate by .300%, respectively. The nucleating agents have no effect on the transformation rate, which, however, is increased slightly in the presence of water and ethanol and significantly in the presence of liquids that are solvents at elevated temperatures or by temperature cycling. As shown previously, the transformation rate of nontreated polymer is greatest near 258C, decreasing at higher and lower temperatures and is increased by tension or uniaxial compression.

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Section: Introductionmentioning

confidence: 99%

Crystallization and Transformation of Polybutene‐1

Kaszonyiova

Rybnikář

Geil

2004

Journal of Macromolecular Science, Part B

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“…Isotactic poly(butene‐1) ( it ‐PB1) is a semicrystalline polyolefin exhibiting pronounced polymorphs and morphologies that depend on its crystallization conditions. Three different polymorphs, designated trigonal (forms I and I′) and tetragonal (form II) and orthorhombic phases have been reported in the literature 1–13. Crystallization in the bulk under atmospheric pressure yields the tetragonal phase with 11/3 helical chains 1–3.…”

Section: Introductionmentioning

confidence: 99%

Isotactic poly(butene‐1) trigonal crystal growth in the melt

Yamashita

Hoshino

Kato

2007

J Polym Sci B Polym Phys

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Crystal growth of the trigonal form of isotactic poly(butene‐1) (it‐PB1) was successfully observed in the melt at atmospheric pressure. The growth rate of trigonal crystals was obtained by in situ optical microscopy. It is one hundredth that of it‐PB1 tetragonal crystals. The growth rate of trigonal crystals, as well as that of tetragonal crystals, shows supercooling dependence derived from the nucleation theory. The value of the kinetic constant K of trigonal crystals is about 3.3 times larger than that of tetragonal crystals. The value of the pre‐exponential factor G0 of trigonal crystals was found to be 41 times as large as that of tetragonal crystals. The difference between these K values can be attributed to the conformational entropy of the ethyl side groups in a nucleating stem. The discrepancy found in the values of G0 could be explained by introducing pinning and nucleation barriers, which originate from the crystal thickness δlc, which does not depend on the crystallization temperature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 684–697, 2007

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“…If we assume a simple case where X1 =X2 and thus at may be neglected, eq 8 reduces to ( 9) Replacing @ in eq 1 with @, of eq 9, we obtain log( log Vo-V=) = log (k/2.303)+log t (10)…”

Section: Crystal Trans/ Ormation In Unstrained Samplesmentioning

confidence: 99%

Rheo-Optical Studies of High Polymers. XXI. The Deformation Process and Crystal Transformation in Polybutene-1

Asada

Sasada

Onogi

1972

Polym J

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ABSTRACT:The crystal transformation from modification 2 to modification 1 in unstrained polybutene-I films was observed by the infrared absorption and refractive index methods. The crystal transformation and orientation during stress-strain measurements were also observed by means of the infrared dichroism method developed by us. The crystal transformation in a fresh sample begins at about 30 min after the sample preparation, and the degree of transformation increases with increasing time until it reaches about 0.9. at 50 hr and 1.0 about 3 weeks after the sample preparation. The rate of crystal transformation could be expressed by an equation of the same form as that for the one-dimensional crystallization rate.Stress-strain curves, degree of crystal transformation vs. strain curves as well as infrared dichroic ratio vs. strain curves for film specimens having different initial degrees of crystal transformation differ remarkably. On the basis of these experimental results, the deformation and crystal transformation processes during stree-strain measurements under constant rate of elongation are discussed.

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Infrared investigations of the polymorphic modifications of polybutene‐1

Cited by 71 publications

References 7 publications

Crystallization and Transformation of Polybutene‐1

Crystallization and Transformation of Polybutene‐1

Isotactic poly(butene‐1) trigonal crystal growth in the melt

Rheo-Optical Studies of High Polymers. XXI. The Deformation Process and Crystal Transformation in Polybutene-1

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