A new approach to the continuum theory of birefringence of oriented polymers

Vries, H. de

doi:10.1007/bf01382363

Cited by 115 publications

(104 citation statements)

References 42 publications

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“…The value of Dn o for PP fiber was taken to be 0.045. 20 Figure 10 shows the relationship between the optical orientation factor of staple PP samples and fibers deniers. It is clear that as denier value increases, the optical orientation factor is decreased.…”

Section: Resultsmentioning

confidence: 99%

The influence of fiber fineness on physical characteristics of staple polypropylene fibers spun at different pumping speeds

Zarrebini

Mahmoudi

El‐Bakary

et al. 2009

J of Applied Polymer Sci

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Melt spinning and pump speed conditions are described for five samples of staple polypropylene PP fibers of different fineness. The influence of fiber fineness or denier on the physical characteristics of staple PP fibers spun at different pump speeds was studied. Optical anisotropy was measured using two-beam interference microscopy. Enthalpy and degree of crystallinity were measured using differential scanning calorimetry technique for studied fibers. The relation between the fiber diameter, crimp ratio, tenacity, and degree of orientation with the fiber denier are given. A selection of microinterferograms of fibers is given for illustration.

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Section: Resultsmentioning

confidence: 99%

The influence of fiber fineness on physical characteristics of staple polypropylene fibers spun at different pumping speeds

Zarrebini

Mahmoudi

El‐Bakary

et al. 2009

J of Applied Polymer Sci

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“…been previously determined to be 0.055 17 18,19 isotropic polarizability, (11) which is the same function named by Hermans' 20 isotropic refractive index,…”

Section: Theoretical Considerationmentioning

confidence: 99%

Optothermal properties of fibers: 12-Interferometric investigation for thermally treated viscose fibers

Fouda

Seisa

Oraby

1999

J. Appl. Polym. Sci.

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ABSTRACT:The present article studies the structure of annealed viscose fibers interferometrically at a constant temperature of 100 { 1ЊC at different times. The Pluta polarizing interference microscope has been used for determining the mean refractive indices and mean birefringence. The results were used to calculate the optical orientation function and the angle of orientation. The value ( Da/3a 0 ), which depends on the molecular structure of the polymer, remains constant. Relationships between the mean refractive indices, birefringence, isotopic refgractive index, and polarizabilities per unit volume with different times were given for these fibers. The samples were subjected to X-ray diffraction to clarify the variation of crystallinity with the annealing conditions. Differential thermal analysis measurements were used to determine the glass transition temperature of viscose fiber. Measurements of the volume swelling parameter of the viscose fibers with different liquids were given. Also, determinations of Cauchy's constants, dispersive power, and dielectric constant at infinity were carried out. Illustrations are given using graphs and microinterferograms.

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“…The isotropic refractive index value of 1.635 for the crystalline phase 63 and the bond polarizabilities summation for the fully stretched chain yield the crystalline birefringence value, ⌬ cryst max = 0.3215. Earlier works, e.g., Ref.…”

Section: ͑24͒mentioning

confidence: 99%

“…X m = c X c / , where the bulk density, = c X c + a ͑1−X c ͒ and c = 1.457 kg/ m 3 , is the density for the crystalline phase. 63 Thus, in the absence of any crystallization, the length of the amorphous region between walls of negligible thickness is h = h 0 = ͉h 0 ͉ ͑DP=DP 0 ͒ , where ͉h 0 ͉ ͑DP=DP 0 ͒ is the unperturbed amorphous intercrystal separation, with polymer chains consisting of the initial number of monomers, DP 0 . When =1, h = h 0 = ͉h 0 ͉ ͑DP=DP 0 ͒ .…”

Section: Incorporation Of Strain-induced Crystallization Effectmentioning

confidence: 99%

Elasticity and photoelasticity relationships for polyethylene terephthalate fiber networks by molecular simulation

Nayak

Das

Nanavati

2008

The Journal of Chemical Physics

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We present a framework for the development of elasticity and photoelasticity relationships for polyethylene terephthalate fiber networks, incorporating aspects of the primary molecular structure. Semicrystalline polymeric fiber networks are modeled as sequentially arranged crystalline and amorphous regions. Rotational isomeric states-Monte Carlo simulations of amorphous chains of up to 360 bonds ͑degree of polymerization, DP= 60͒, confined between and bridging infinite impenetrable crystalline walls, have been characterized by ⍀, the probability density of the intercrystal separation h, and ⌬␤, the polarizability anisotropy. ln ⍀ and ⌬␤ have been modeled as functions of h, yielding the chain deformation relationships. The development has been extended to the fiber network to yield the photoelasticity relationships. We execute our framework by fitting to experimental stress-elongation data and employing the single fitted parameter to directly predict the birefringence-elongation behavior, without any further fitting. Incorporating the effect of strain-induced crystallization into the framework makes it physically more meaningful and yields accurate predictions of the birefringence-elongation behavior.

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A new approach to the continuum theory of birefringence of oriented polymers

Abstract: A new approach to the continuum theory of birefringence of oriented polymers Hendrik de VriesWith 4 figures and 4 tables (Received September 30, 1978) M 888 de Vries, A new approach to the continuum theory of birefrineence of oriented polymers 22 7 15"

Cited by 115 publications

References 42 publications

The influence of fiber fineness on physical characteristics of staple polypropylene fibers spun at different pumping speeds

The influence of fiber fineness on physical characteristics of staple polypropylene fibers spun at different pumping speeds

Optothermal properties of fibers: 12-Interferometric investigation for thermally treated viscose fibers

Elasticity and photoelasticity relationships for polyethylene terephthalate fiber networks by molecular simulation

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