Uniaxial orientation of linear low density polyethylene

Pezzutti, José L.; Porter, Roger S.

doi:10.1002/app.1985.070301104

Cited by 13 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown by WAXD studies26 the specimens used in the present work are clearly fibrous; therefore it is appropriate to take An¡m = 0.12, as proposed by Wedgewood and Seferis.11 For the crystalline phase we have taken An°= 0.057, since this is the value most frequently encountered in the literature. 24,26,27 Using these values of the intrinsic birefringences together with the measured values of AnT, {" and ß, values of were estimated from eq 12. The results are shown in Table I and Figure 8 as a function of draw ratio.…”

Section: Resultsmentioning

confidence: 99%

Drawing-induced changes in the properties of polyethylene fibers prepared by gelation/crystallization

Anandakumaran¹,

Roy²,

Manley³

1988

Macromolecules

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Drawing-induced changes in the properties of polyethylene fibers prepared by gelation/crystallization

Anandakumaran¹,

Roy²,

Manley³

1988

Macromolecules

View full text Add to dashboard Cite

Rheo‐optical fourier‐transform infrared spectroscopy of polymers, 15. Orientational and modificational changes during uniaxial elongation of high‐, low‐ and linear low‐density polyethylenes

Siesler

1989

Makromol. Chem.

View full text Add to dashboard Cite

The transient structural changes of high., low-and linear low-density polyethylenes were studied by simultaneous mechanical and Fourier-tranform infrared (FTIR) spectroscopic measurements. The rheo-optical FTIR data provide a detailed picture of the progress and extent of crystal-axis orientation and orthorhombic-to-monoclinic phase transition during elongation up to 40@% strain. Apart from a higher degree of orientation as a consequence of the mechanical treatment, high-density polyethylene may be differentiated from the low-density types by running through a maximum in the content of monoclinic phase upon neck formation. With reference to the investigated structural changes, the linear low-density polyethylenes generally exhibit a behaviour intermediate to the high-density and low-density types.

show abstract

Small‐Molecule Diffusion in Semicrystalline Polymers as Revealed by Experimental and Simulation Studies

Nilsson

Hedenqvist

Gedde

2010

Macromolecular Symposia

View full text Add to dashboard Cite

Summary: Diffusion of n‐hexane in poly(ethylene‐co‐1‐hexene)s with 15–75 wt.% crystallinity was studied by desorption experiments analyzing data using the Fickian equations with a concentration dependent diffusivity. The effect of the impenetrable crystalline phase on the penetrant diffusivity (D) is described by D = Da/(τβ), where Da is the diffusivity of the amorphous polymer, τ is the geometrical impedance factor and β is a factor describing the constraining effect of the crystals on the non‐crystalline phase. For a polymer with 75 wt.% crystallinity, τβ varied markedly with penetrant concentration (v1a) in the penetrable phase: 1000 (v1a = 0) and 10 (v1a = 0.15). This penetrant‐uptake had no effect on the gross crystal morphology, i.e. β must be strongly dependent on v1a. Samples saturated in n‐hexane exhibited a penetrant‐induced loosening of the interfacial structure, as revealed by an increase in crystal density that require an increased mobility in the interfacial component and by a decrease in the intensity of the asymmetric X‐ray scattering associated with the interfacial component. The geometrical impedance factor has been modelled by mimicking spherulite growth and τ was obtained as the ratio of the diffusivities of the fully amorphous and semicrystalline systems. The maximum τ obtained from these simulations is ca. ten, which suggests that β in the systems with v1a = 0.15 takes values close to unity. The simulations showed that the geometrical impedance factor is insensitive to the ratio of the crystal width and the crystal thickness. A free path length scaling parameter characteristic of the amorphous phase correlated with τ.

show abstract

Uniaxial orientation of linear low density polyethylene

Cited by 13 publications

References 15 publications

Drawing-induced changes in the properties of polyethylene fibers prepared by gelation/crystallization

Drawing-induced changes in the properties of polyethylene fibers prepared by gelation/crystallization

Rheo‐optical fourier‐transform infrared spectroscopy of polymers, 15. Orientational and modificational changes during uniaxial elongation of high‐, low‐ and linear low‐density polyethylenes

Small‐Molecule Diffusion in Semicrystalline Polymers as Revealed by Experimental and Simulation Studies

Contact Info

Product

Resources

About