Infrared studies of drawn polyethylene part I. Changes in orientation and conformation of highly drawn linear polyethylene

Glenz, W.; Peterlin, A.

doi:10.1080/00222347008229369

Cited by 107 publications

(17 citation statements)

References 23 publications

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“…The results for the three samples at the three draw ratios are given in Table I; the values in parentheses for the undrawn materials are those from the X-ray diffraction measurements. The results are in line with those of Glenz and Peterlin [13]. They show a reduction in crystallinity at intermediate draw ratios followed by a recovery towards the initial value.…”

Section: Infra-red Spectroscopic Measurementssupporting

confidence: 92%

“…Although wide-angle X-ray diffraction studies have been reported [11,12] they were concerned with the orientation and the change in crystallite size and in paracrystallinity which occur during drawing. No attempt appears to have been made to measure changes in crystallinity, to supplement the infra-red measurements of Glenz and Peterlin [13]. Such measurements pose problems because of orientation and paracrystallinity effects but they merit study.…”

Section: Introductionmentioning

confidence: 90%

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An infra-red spectroscopic and X-ray diffraction study of cold-drawn high density polyethylene samples

1976

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Three samples of high-density polyethylene, one linear, the second with one ethyl branch per thousand carbon atoms and the third with a comparable concentration of butyl branches, cold drawn at 60 ~ C to elongations of 300,800 and 1600%, have been examined by infra-red spectroscopy and wide-and small-angle X-ray diffraction. The results are consistent with, and give additional information about, the Peterlin model of plastic deformation. The change in crystallinity with draw ratio has been measured by infra-red spectroscopy and a wide-angle transmission X-ray diffraction method that minimizes the effect of the uniaxial orientation of the drawn specimens. Wide-angle measurements by reflection proved to be unreliable. Changes in the relative concentrations of methylene groups in crystalline regions, in gauche conformations and in tie chains in amorphous regions, and the alignment of tie molecules, have been followed by unpolarized and polarized infra-red spectroscopy. Small-angle X-ray diffraction measurements show that microvoids, with average dimensions of 250 and 80 A parallel to and perpendicular to the draw direction respectively, are formed during the transition from the lamellar to the fibrillar structure.

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Section: Infra-red Spectroscopic Measurementssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 90%

An infra-red spectroscopic and X-ray diffraction study of cold-drawn high density polyethylene samples

1976

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“…These results are largely consistent with prior orientation studies of crystalline phase in LLDPE and LDPE blown films by WAXD and polarized IR 2,16,[17][18][19][20][21][22][23][24][25][26] and are typically interpreted in terms of the Keller-Machin I ''row nucleated'' structure. 27,28 Molecular orientation of the blends amorphous phase Many reports 8,11,12,29 have indicated that the amorphous orientation plays an important role on the final properties of the blowing films. In this work, we present an attempt to measure the orientation of the amorphous phase.…”

Section: Molecular Orientation By Polarized Irmentioning

confidence: 99%

“…This band has been assigned to the molecular segments involving gauche conformers present only in amorphous phases. Since the transition moment associated with the 1368 cm À1 band is perpendicular to the chains axis, the orientation of the amorphous phase can be determined by [10][11][12] :…”

mentioning

confidence: 99%

Correlations between processing parameters, morphology, and properties of blown films of LLDPE/LDPE blends, part 2: Crystalline and amorphous biaxial orientation by WAXD pole figures

Branciforti¹,

Guerrini²,

Machado³

et al. 2006

J of Applied Polymer Sci

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ABSTRACT:The biaxial molecular orientation of blown films made of blends of linear low density polyethylene (LLDPE) with low density polyethylene (LDPE) was characterized by two different methods: complete pole figures obtained by wide angle X-rays diffraction (WAXD) and polarized infrared spectroscopy (IR) using the Krishnaswamy approach. The molecular orientation of the blends amorphous phase was also evaluated by polarized IR. The crystallinity of the blown films was determined by WAXD. A good correlation between the X-ray pole figures and the polarized IR results was obtained. At all blends compositions, it was shown that the a-axis of the polyethylene orthorhombic cell was preferentially oriented along the machine direction, the orientation degree along this direction increasing with the increase of the LDPE amount in the blends. The b-axis changed its preferential orientation from film thickness in the 100/0 LLDPE/LDPE film to along the transverse direction with increasing LDPE in the blends. The c-axis changed its orientation from orthogonal to normal direction in the 100/0 LLDPE/LDPE film to along the film thickness with increasing LDPE in the blends. Polarized IR characterization showed a negligible orientation of the amorphous phase. The amount of crystallinity was dependent on blend composition decreasing with the increase of LDPE content in the blends.

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“…Although in the past IR spectroscopy was extensively used to determine orientation of the polymer chains through dichroic ratio calculations 1 in oriented polymer systems (30)(31)(32)(33)(34)(35), only recently the issue of surface crys-1 Dichroic ratio is defined as D = A^/A ± where D is the dichroic ratio and Ay and A ± are absorbances obtained parallel and perpendicular, respectively, to the polymer draw directions. tallinity has been addressed (36).…”

Section: Ftir Spectroscopy In Polymer Analysismentioning

confidence: 99%

Fourier Transform Infrared and Fourier Transform Raman Spectroscopy of Polymers

Urban

1993

Advances in Chemistry

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This chapter covers the fundamental principles and current applications of Fourier transform (FT) infrared and Fourier transformRaman spectroscopies as utilized in the analysis of polymeric materials. The primary emphasis of the first part is on the principles and advantages of these interferometric methods, whereas the remaining sections illustrate numerous applications focusing on the structure--property considerations in polymers. Particular attention is given to the most recent developments in FT analysis and includes examples of structural and conformational analysis of polymers, biological studies, and the applications of FT infrared and Raman microscopy to remote measurements. The differences and the complementary nature of infrared and Raman spectroscopies are also presented. EJXPERIMENTAL SCIENCES HAVE BEEN PROFOUNDLY INFLUENCED by the development of novel instrumentation. Virtually all scientific instrumentation is now under computer control, and sophisticated, faster data collection allows scientists to channel their resources more effectively toward particular goals. The sophistication of many current physical approaches mandates the use of highly sensitive, fast instruments and reasonably powerful data acquisi tion computers to attain insights about fundamental aspects of processes under investigation. Examples of such sophisticated interplay are infrared and

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Infrared studies of drawn polyethylene part I. Changes in orientation and conformation of highly drawn linear polyethylene

Cited by 107 publications

References 23 publications

An infra-red spectroscopic and X-ray diffraction study of cold-drawn high density polyethylene samples

An infra-red spectroscopic and X-ray diffraction study of cold-drawn high density polyethylene samples

Correlations between processing parameters, morphology, and properties of blown films of LLDPE/LDPE blends, part 2: Crystalline and amorphous biaxial orientation by WAXD pole figures

Fourier Transform Infrared and Fourier Transform Raman Spectroscopy of Polymers

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