Infrared characterization of polymorphism in polybutene‐1

Luongo, J. P.; Salovey, R.

doi:10.1002/pol.1966.160040613

Cited by 64 publications

(42 citation statements)

References 9 publications

(3 reference statements)

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“…The band at 923 cm −1 was not employed because it overlapped seriously with the band at 905 cm −1 . The band at 816 cm −1 is also sensitive to form I nucleation, which can be also regarded as the characteristic band of from I . From the beginning, the peak area at 816 cm −1 increased (see Figure 5D).…”

Section: Resultsmentioning

confidence: 92%

“…IR bands of PB‐1 have been assigned successfully . For example, both bands at 905 and 923 cm −1 were assigned to the coupling of the CH 2 rocking mode in the main chain r (CH 2 ) m with the CH 3 rocking mode in the ethyl group r a′ (CH 3 ).…”

Section: Resultsmentioning

confidence: 99%

“…Similar finding was found in our IR bands of PB-1 have been assigned successfully. [56,57,59] For example, both bands at 905 and 923 cm −1 were assigned to the coupling of the CH 2 rocking mode in the main chain r(CH 2 ) m with the CH 3 rocking mode in the ethyl group r a 0 (CH 3 ). The band at 816 cm −1 was assigned to coupling vibration of the CH 2 rocking mode in the main chain r(CH 2 ) m and the CC stretching mode in the ethyl group ν s (CC) s ; the band at 850 cm −1 was from the coupling of the CH 3 rocking mode in the ethyl group r a 0 (CH 3 ) and the CC stretching mode in the main chain ν s (CC) m , while the band at 1208 cm −1 was due to the coupling of the CH 2 twisting t(CH 2 ) m and the CH wagging modes in the main chain ω(CH).…”

Section: The Role Of Annealing Temperaturesmentioning

confidence: 99%

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In situ POM and FTIR investigation on quiescent phase transition of polybutene‐1 from form II to form I

Ding

Zheng

et al. 2020

Polymer Crystallization

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Despite extensive investigations in the past decade, the factors affecting the phase transition of polybutene‐1 (PB‐1) form tetragonal form II to hexagonal form I were not clarified completely. In this study, quiescent phase transitions of PB‐1 within different morphological of crystals at different temperatures were investigated employing polarized optical microscopy and Fourier transform infrared spectroscopy. Results indicate that the phase transition depends not only on intercrystalline links but also on the lamellar thickness. The phase transition always occurs spontaneously first in thick form II lamellae. The intercrystalline links have opposite effects in the early and later stages. In the early stage, it can promote form I nucleation in some form II clusters, where these clusters were subjected to inward tensions of intercrystalline links. While in the later stage, it retards form I growth since subjecting to outward tensions of intercrystalline links. This study helps to identify more effective method to accelerate forms II‐I phase transition.

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Section: Resultsmentioning

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Section: The Role Of Annealing Temperaturesmentioning

confidence: 99%

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In situ POM and FTIR investigation on quiescent phase transition of polybutene‐1 from form II to form I

Ding

Zheng

et al. 2020

Polymer Crystallization

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“…mainly in chain scission [4], the eect on II → I transition is not reported uniformly [5]. Irradiation in air produced radicals which were scavenged by oxygen and this prevented crosslinking.…”

Section: The Electron and Gamma Irradiation Of Pb-1 Resultsmentioning

confidence: 99%

The Effect of Electron Irradiation on Polybutene-1 and Its Ethylene Copolymers

2012

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The beta irradiation, as one of several possibilities how to modify the polymer properties resulted in isotactic polybutene-1 (PB-1) and its random copolymers with ethylene (E) mainly in chain scission without chain cross-linking. The original phase I did not change by irradiation, only the transformation rate of phase II to I increased with the irradiation dose and ethylene groups in PB-1/E copolymers. Beta irradiation decreased the sample crystallinity, crystal size, and perfection.

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“…Values of 14.3 kcaljmol and 12.7 kcaljmol were obtained for the rheo-optical and mechanical relaxation processes respectively. These activation energies ( 4) where (11/r)c, (11/r)., and (11/r)r are the contributions to the total birefringence form the crystalline region, the amorphous region, and form birefringence, respectively. In the case of polybutene-!, (11/r)c must be expressed by the following equation: ( 5) where and 11h are the intrinsic birefringence of mod.…”

Section: Time Dependent Birefringence and Relaxationmentioning

confidence: 99%

Orientation and Crystal Transformation in Polybutene-1 under Stress Relaxation

Tanaka

Sugimoto

Asada

et al. 1975

Polym J

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ABSTRACT:The stress relaxation and birefringence relaxation of polybutene-1 were simultaneously measured at different temperatures ranging from 14 to 80°C. The relaxation curves obtained could be well superposed by vertical and horizontal shifts at short relaxation times, during which little crystal transformation takes place. However, at long relaxation times, various nonsuperposed curves branched out from the master curve. Such branching out cannot be observed for polyethylene and polypropylene. The superposed part represents the orientation of crystallites of mod. II, whereas the nonsuperposed part must result from a crystal transformation. Thus, the relaxation processes in polybutene-! involve the crystallite orientation and crystal transformation from mod. II to mod. I.The intrinsic birefringences for the mod. I and mod. II crystals could be evaluated from the strain-optical coefficients for the superposed and nonsuperposed parts along with orientation functions of mod. I and mod. II crystallites, as determined by X-ray methods.KEY WORDS Rheo-Optics I Crystal Transformation 1 Orientation I Stress Relaxation I Polybutene-1 I Intrinsic Birefringence 1As mentioned in a previous paper, 1 it is well known that the tetragonal crystal modification (mod. II) in polybutene-1 transforms into the hexagonal crystal modification (mod. I) when a fresh sample of this material is allowed to stand after preparation. 2 -9 The crystal transformation is also accelerated by stretching. 1 • 8 Therefore, the variation of the mechanical properties of this material with time can be fully understood only when this transformation is taken into consideration.observed under a constant strain. However, such an effect has not hitherto been studied at all.In a previous paper/ therefore, the infrared dichroism technique which had been developed by us was employed to elucidate the crystal transformation and orientation during stressstrain measurements; this technique was found to be very powerful for separating the contribution of the crystal transformation to the stress-strain behavior from that of the crystal orientation. It was anticipated from the results obtained in this study that the crystal transformation in polybutene-1 must also affect the stress relaxation and rhea-optical relaxation phenomena * To whom all communication should be addressed.In this paper, therefore, the stress relaxation and birefringence relaxation were simultaneously measured by means of the time-dependent birefringence method for a fresh polybutene-1 film in the course of aging at different temperatures. Combining results obtained by such viscoelastic and rhea-optical measurements with those from X-ray diffraction measurements, the effect of crystal transformation on the relaxation phenomena, which cannot be observed for polyethylene and polypropylene, 10 -12 was separated from that of crystallite orientation. The intrinsic birefringences for the modifications I and II crystals were also evaluated and discussed. EXPERIMENTAL Material and CharacterizationCommer...

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Infrared characterization of polymorphism in polybutene‐1

Cited by 64 publications

References 9 publications

In situ POM and FTIR investigation on quiescent phase transition of polybutene‐1 from form II to form I

In situ POM and FTIR investigation on quiescent phase transition of polybutene‐1 from form II to form I

The Effect of Electron Irradiation on Polybutene-1 and Its Ethylene Copolymers

Orientation and Crystal Transformation in Polybutene-1 under Stress Relaxation

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