Infra-red study of poly(1-pentene) and poly(4-methyl-1-pentene)

Gabbay, S.M.

doi:10.1016/0032-3861(76)90080-x

Cited by 18 publications

(7 citation statements)

References 10 publications

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“…The 1400−1500 cm -1 region is stated to be associated with side chain atoms, while all the others featured above are mixed bands with contributions from both side chain and main chain groups. The infrared bands at 809 and 844 cm -1 in isotactic P4MP1 are sensitive to tacticity and crystallinity . From the normal-mode analysis, similar conclusions were reached by Bahuguna et al In our work on Raman spectroscopy, the bands closest to these should feature in the region 750−850 cm -1 .…”

Section: Resultssupporting

confidence: 89%

“…The known spectroscopic background of P4MP1, however, is not well established. From what is known, , we can say the following concerning the above band regions. The 1400−1500 cm -1 region is stated to be associated with side chain atoms, while all the others featured above are mixed bands with contributions from both side chain and main chain groups.…”

Section: Resultsmentioning

confidence: 99%

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Unusual Pressure-Induced Phase Behavior in Crystalline Poly(4-methylpentene-1): Calorimetric and Spectroscopic Results and Further Implications

1999

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The polymer poly(4-methylpentene-1), P4MP1, displays an unusual pressure−temperature (p, T) phase diagram raising also issues of wider generality for the phase behavior of single-component condensed matter systems. Previous exploration of this phase behavior through X-ray diffraction has been extended through high-pressure calorimetry, Raman spectroscopy, and time-resolved in situ X-ray scattering. As a result the p, T phase diagram, previously postulated on structural evidence is now supported by heat effects defining phase transitions of first order along the appropriate p, T phase lines with signs which are self-consistent in accord with the unusual nature of some of the transitions involved. The latter include (1) amorphization under pressure, (2) ordering on heating and disordering on cooling, and (3) sign inversion of the pressure coefficient of the melting point, dT m/dp, with increasing pressure. The newly recorded heat effects, consistent with the above, include exotherms on amorphization and endotherms on crystallization. The most salient features of the phase diagram involving effects 1−3 are as follows: (α) a re-entrant melt phase region and (β) the assertion that the amorphous material can be compressed to smaller volumes than the crystals. While seemingly counterintuitive, pertinent historical precedents are being quoted. All the above conflicts with the tenets of the widely held Kauzmann restrictions (“paradox”), which it seemingly invalidates. A possible way to reconcile this conflict is by invoking a theoretical explanation on metals existing in the literature. In structural terms, high-pressure Raman spectroscopic and time-resolved X-ray scattering evidence have been obtained. Further issues arising such as the distinction, or otherwise, between fluid and solid “amorphous” phases and their incorporation into phase diagrams are being discussed, and the still open-ended question concerning the molecular nature of the pressure generated amorphous material is being raised.

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Unusual Pressure-Induced Phase Behavior in Crystalline Poly(4-methylpentene-1): Calorimetric and Spectroscopic Results and Further Implications

1999

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“…The approximate degree of isotacticity of crystalline poly-(3-methyl-l-butene) was determined from the ratio of the absorbance at 778 cm-1 to 1180 cm-1 (140). The IR spectra of isotactic poly(l-pentene), poly (4-methyl-l-pentene), and atactic poly(4-methyl-l-pentene) were reported by Gabbay and Stivala (127).…”

Section: Gas Chromatographymentioning

confidence: 83%

Analysis of high polymers

Cobler¹,

Chow²

1977

Anal. Chem.

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“…For PMP, a vibration specific to a single phase is not known. He and Porter,24 however, used the dichroism of the 918‐cm −1 band, a rocking mode vibration from two methyl groups,25 to follow the sample orientation as a function of extension.…”

Section: Methodsmentioning

confidence: 99%

Microporous membranes of isotactic poly(4‐methyl‐1‐pentene) from a melt‐extrusion process. II. Effects of thermal annealing and stretching on porosity

Johnson

Wilkes

2002

J of Applied Polymer Sci

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A two-part study utilizing isotactic poly(4-methyl-1-pentene) (PMP) was undertaken to investigate a three-stage process (melt-extrusion/annealing/uniaxial stretching) (MEAUS) utilized to produce microporous films. In this report, the thermalannealing (second stage) and subsequent uniaxial-stretching (third stage) results of selected PMP films from three resins, labeled A, B, and C, are discussed. From sequential analysis of the effect each stage had on the resulting microporosity, it was discovered that the melt-extruded precursor morphology and orientation, as a consequence of the first-stage extrusion parameters and resin characteristics, were crucial to controlling the membrane permeability. The annealing parameters were also critical, where a temperature of 205°C applied for 20 min under no tension was the optimum annealing condition for producing highly microporous PMP films upon stretching. For the conditions studied, the stretching parameters that were found to be the optimum for producing the desired characteristics in the final film were cold-and hot-stretch temperatures of 70 and 180°C, respectively. The cold-and hot-stretch extension levels concluded to be the best were a cold-stretch extension of 80%, followed by hot stretching to 90%, and, thus, a total overall extension level of 170% for the processing window studied. However, these results were only with respect to resin A films, while resin B and C samples could not be produced into microporous films via the MEAUS process.

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Infra-red study of poly(1-pentene) and poly(4-methyl-1-pentene)

Cited by 18 publications

References 10 publications

Unusual Pressure-Induced Phase Behavior in Crystalline Poly(4-methylpentene-1): Calorimetric and Spectroscopic Results and Further Implications

Unusual Pressure-Induced Phase Behavior in Crystalline Poly(4-methylpentene-1): Calorimetric and Spectroscopic Results and Further Implications

Analysis of high polymers

Microporous membranes of isotactic poly(4‐methyl‐1‐pentene) from a melt‐extrusion process. II. Effects of thermal annealing and stretching on porosity

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