Morphological study of HDPE blown films by SAXS, SEM and TEM: a relationship between the melt elasticity parameter and lamellae orientation

Prasad, Arun; Shroff, Ramesh N.; Rane, S.; Beaucage, Gregory

doi:10.1016/s0032-3861(00)00612-1

Cited by 59 publications

(58 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1A). In the literature, structures of this kind are referred to as row-structures, Keller-Machin structures, or layered lamellar structures [29][30][31][32][33][34][35][36][37]. The lamellae are assembled into columns and are predominantly located layerwise perpendicularly to the extrusion axis ( Fig.…”

Section: Structure Of Initial Hdpementioning

confidence: 99%

“…Being crystallized under the conditions of a tensile stress, a melted polymer may form samples containing anisotropically arranged stacks of lamellae, which are predominantly oriented perpendicularly to an extrusion axis [29][30][31][32][33][34][35][36][37]. Such anisotropic structures, which are referred to as row-structures, are more convenient for investigating structural rearrangements that accompany the deformation of semicrystalline polymers, because these structures are characterized by a smaller number of possible orientations relative to an applied force.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The structural evolution of high-density polyethylene during crazing in liquid medium

Yarysheva

Rukhlya

Yarysheva

et al. 2015

European Polymer Journal

View full text Add to dashboard Cite

Section: Structure Of Initial Hdpementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The structural evolution of high-density polyethylene during crazing in liquid medium

Yarysheva

Rukhlya

Yarysheva

et al. 2015

European Polymer Journal

View full text Add to dashboard Cite

“…In addition, it has been demonstrated that it is also useful to evaluate the orientation of crystalline lamellae from a SAXS pattern. 22 In this case, the Hermans orientation function f 2 is given by where with I i being the scattered intensity at the ith azimuthal angle i . In our case, this calculation was done by azimuthal cake integrations with three cake sizes in order to have an estimation of the error in the values of f 2 .…”

Section: Orientation Functionmentioning

confidence: 99%

Influence of Shear on the Templated Crystallization of Poly(butylene terephthalate)/Single Wall Carbon Nanotube Nanocomposites

et al. 2007

View full text Add to dashboard Cite

The templating effect due to single wall carbon nanotubes (SWCNT) and shear on polymer crystallization has been studied in films of nanocomposites based on poly(butylene terephthalate) (PBT). With the use of a rheometer, a step shear was applied to the molten polymer. After shear cessation, the sample was immediately cooled down to the crystallization temperature. Crystalline development, in real time, was investigated by small-angle X-ray scattering (SAXS) with a synchrotron radiation beam parallel to the film. SWCNT bundles template polymer lamellae to grow perpendicular to the SWCNT surfaces in a shish-kebab fashion even under quiescent conditions. Because of the power of SWCNT as nucleating agents, the shear rate has a minor effect on the crystallization kinetics. However, the fraction of oriented material increases significantly with shear rate. The results indicate that SWCNT act as nuclei stabilizers, providing surfaces which favor polymer crystallization.

show abstract

“…Therefore, polarized FTIR measurements were performed to study the crystalline orientation of the HDPE precursor films. 38 Consequently, with increasing the draw ratio the f a value tends to decrease, so that for the films with higher draw ratios f a shows negative values, meaning a movement to align to the transverse direction (TD) and normal direction (ND) of the films, i.e., TD-ND plane, for the higher applied draw ratios. Figure 1(a) presents that for the film DR 25.5, f a holds a positive value.…”

Section: Orientation Of Hdpe Cast Filmsmentioning

confidence: 99%

Influence of precursor film microstructure on properties of HDPE microporous membranes prepared by stretching

Yadegari

Morshedian

Khonakdar

et al. 2017

J of Applied Polymer Sci

View full text Add to dashboard Cite

Oriented HDPE films having a stacked lamellar morphology were prepared to develop microporous membranes through cast film extrusion followed by stretching. Applying higher draw ratios (DR) and annealing the cast films improved crystal alignments remarkably. It was shown the improvement in c-axis orientation upon annealing was more significant for the films prepared with lower DR. Furthermore, applying Raman spectroscopy, the amorphous mass fraction of the films was obtained. Subsequently, considering a three-phase structure (i.e., crystal, amorphous and interphase), the interphase content of the films was also determined. A distinct DR dependence of the interphase content was noticed. It was observed that in addition to crystal perfection upon annealing, the amorphous phase fraction was also decreased due to possibly increase in free volume, promoting lamellar separation and cavitation during the subsequent stretching step. SEM images of the membranes surfaces as well as their normalized water vapor transmission rate (WVTR) values indicated a more uniform pore formation and increased permeability with DR. Furthermore, it was found that lower interphase content in the films with higher DR favors lamellar separation. However, permeability in the stretched precursor films with DR higher than a certain level (DR 5 93) was not improved significantly. Moreover, crystallinity and crystal orientation of produced membranes were investigated.

show abstract

Morphological study of HDPE blown films by SAXS, SEM and TEM: a relationship between the melt elasticity parameter and lamellae orientation

Cited by 59 publications

References 31 publications

The structural evolution of high-density polyethylene during crazing in liquid medium

The structural evolution of high-density polyethylene during crazing in liquid medium

Influence of Shear on the Templated Crystallization of Poly(butylene terephthalate)/Single Wall Carbon Nanotube Nanocomposites

Influence of precursor film microstructure on properties of HDPE microporous membranes prepared by stretching

Contact Info

Product

Resources

About