Swelling of solution formed polyethylene crystals

Ergoz, E.; Mandelkern, L.

doi:10.1002/pol.1972.110100809

Cited by 16 publications

(5 citation statements)

References 15 publications

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“…The new experimental results that were obtained, under the same crystallization conditions as those previously reported (2), are given in Figure 1. Also plotted are the previous results for M 2 2 X lo4 (2). For the isothermal crystallization at 80 and 88"C, at molecular weights less than about 1-2 X l o 4 , there is an increase in the long spacing of the dry samples as the molecular weight decreases.…”

mentioning

confidence: 82%

“…The data can be represented by the indicated straight line. All the data for molecular weights greater than 20,000 cannot be represented by this straight line because of the invariance of the density (13) and the long spacing in this range of molecular weights (2)(3)(4) while the increase of the long spacing on swelling is not constant (2). However, at the higher molecular weights, A is a constant, i.e., the swelling becomes invariant; and in this range, as is indicated, the quantity A/L, follows the same straight line.…”

Section: Characterization Of Fractionsmentioning

confidence: 99%

“…It has been found (1,2) that the low-angle diffraction maxima, or long spacings, which are characteristic of solution-formed crystals of polyethylene increase reversibly when they are placed in contact with certain liquids at room temperature. This increased spacing can be attributed to the swelling of the disordered interfacial layer (1,2). The previous work with high-molecularweight fractions sustained the concept that under isothermal crystallization conditions the long spacings of the dried crystals were independent of molecular weight (2-4).…”

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confidence: 99%

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Swelling of solution‐formed polyethylene crystals of low molecular weight

Kloos

Mandelkern

1979

J. Polym. Sci. B Polym. Lett. Ed.

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confidence: 82%

Section: Characterization Of Fractionsmentioning

confidence: 99%

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confidence: 99%

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Swelling of solution‐formed polyethylene crystals of low molecular weight

Kloos

Mandelkern

1979

J. Polym. Sci. B Polym. Lett. Ed.

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“…The mean-square electron density fluctuation is (Av2)s = [wcw,(~c -+ waws(va -7s)' + wcwa(vcva)']/(1 + ws) (6) Values of the mean-square electron density fluctuation computed from eq. (6) are plotted versus the crystalline volume fraction for various electron densities vs of the swelling agent [ Fig.…”

Section: Saxs Intensitymentioning

confidence: 99%

Anisotropic swelling of doubly oriented nylon‐11 with a lamellar structure

Dosière

Point

1984

J. Polym. Sci. Polym. Phys. Ed.

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Rolled smaples of nylon‐11 annealed in formic acid (90%) at 80°C remain doubly oriented and have the same allotropic form as filter mats of single crystals. the basal planes of the crystals are parallel to (00l) planes. the long spacing is larger than in filter mats. Experimental swelling results obtained on such samples are discussed on the basis of two extreme models, the lamellar and the switchboard models. The long spacing dy and the length of the sample (along 0Y) change reversibly by the same proportion during swelling. Insertion of solvent between lamellae is invoked to explain such changes of dimension. As linear swelling ratios computed from macroscopic dimensions and SAXS measurements can reach 100%, lamellar crystals are only bonded by a few chains. The large increase of the SAXS intensity observed when annealed doubly oriented samples of nylon‐11 are wetted with allylic alcohol cannot be explained on the basis of the switchboard model but only with a three‐phase lamellar model. These three phases are the crystalline phase, the fold region, and a dilute solution of polymer in the swelling agent.

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“…The thermodynamical condition of the swelling equilibrium in a three-component system can be written as (5) …”

Section: Thermodynamic Treatment Of Polymer-solventnonsolvent Three-cmentioning

confidence: 99%

Swelling Equilibrium and the Superstructures of Uniaxially Oriented α Nylon 6 in Solvent Mixtures

Zheng

Nojima

Yamane

et al. 1989

Polym J

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ABSTRACT:A small angle X-ray scattering (SAXS) study of uniaxially oriented rx nylon 6 at swelling equilibrium was carried out based on a paracrystalline macrolattice model. The results supported the conventional assumption that the crystalline core is unpenetrable to the swelling agent. Reasonable thermodynamic interaction parameters were obtained, and excellent agreement between the dimensions of the tie molecules from the thermodynamic experiment and SAXS data was obtained, indicating that the tie molecules were highly extended at maximum swelling degree.KEY WORDS Swelling Equilibrium / Three-Component System / Interaction Parameter/ rx Nylon 6 / Small Angle X-Ray Scattering/ SAXS Model Fitting / Crystallite / The swelling behavior of the semicrystalline polymers has been investigated 1 -10 using the SAXS method. In all these investigations, however, discussions have exclusively been confined to the change in the long spacing, using only a portion of the information contained in the SAXS pattern. Recently, a model which accounts for SAXS pattern from uniaxially oriented semicrystalline polymers has been proposed by This model makes it possible to clarify the behavior of the crystallites in polymers when swollen, and to examine the validity of the conventional assumption that the crystalline phase is unpenetrable to swelling agent. The assumption was first introduced by Rogers et al. 14 and adopted by many other authors 15 -19 to apply the theory 20 of swelling equilibrium for crosslinked rubber to semicrystalline polymer.In this work, the SAXS study of uniaxially oriented rx nylon 6 at swelling equilibrium was made, and the superstructure parameters were obtained using the above model. To make clear the dependence of the superstructure on the degree of swelling, measurements were performed for a series of mixtures of the solvent (swelling agent) with nonsolvent of different concentrations, hence different solvent activities. The nonsolvent was chosen on the basis of its lack of affinity for the polymer and miscibility with the solvent. The thermodynamic treatment was attempted to shed light on how the swelling theory is applicable to the present three-component, polymer-solventnonsolvent systems.For nylon 6 a large number of studies 21 -3 z has been conducted on the effects of swelling treatment on the morphology and the properties, but no report deals with the structural behavior at swelling equilibrium.

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Swelling of solution formed polyethylene crystals

Cited by 16 publications

References 15 publications

Swelling of solution‐formed polyethylene crystals of low molecular weight

Swelling of solution‐formed polyethylene crystals of low molecular weight

Anisotropic swelling of doubly oriented nylon‐11 with a lamellar structure

Swelling Equilibrium and the Superstructures of Uniaxially Oriented α Nylon 6 in Solvent Mixtures

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