Morphology and Orientation of Crystallites of Simultaneous Biaxially Stretching Ultra-High Molecular Weight Polyethylene Films Prepared by Gelation/Crystallization from Solutions

Nakashima, Teruo; Xu, Chunye; Bin, Yuezhen; Matsuo, Masaru

doi:10.1295/polymj.33.54

Cited by 10 publications

(18 citation statements)

References 44 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…17,18 The comparison between the experimental and re-calculated results was done in the previous paper. 11 As shown in the previous paper, 11 the re-calculated functions calculated from the orientation distribution function of crystallites were in good agreement with the observed functions, indicating that the experimental functions have high accuracy. To facilitate understanding the results, thes re-calculated curves are shown again as dotted curves in this paper.…”

Section: Application To Oriented Crystallization Of Polyethylene Undesupporting

confidence: 79%

“…In accordance with the orientational mode of the (200) plane, the (110) plane takes two modes. This mode was discussed elsewhere 11,16 and the mathematical geometrical arrangement shall be discussed later in this paper.…”

Section: Characteristics Of Test Specimensmentioning

confidence: 93%

“…Accordingly, we adopted a small but refined instrument to stack a number of thin films as shown in Figure 1. 11 In such a stacked condition, measurements of the X-ray diffraction intensity could be performed by using a horizontal scanning type goniometer, operating at a fixed time step scan of 0.1/40 s over a range of twice the Bragg angle 2 B from 15 to 60…”

Section: Experimental Methodsmentioning

confidence: 99%

“…In doing so, this paper adopts the orientation distribution functions of the reciprocal lattice vectors of crystal planes measured elsewhere. 11,12 The simultaneous biaxially stretching was carried out using ultra-high molecular weight polyethylene (UHMWPE) dry gel films prepared by gelation/crystallization from solutions.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Segmental Orientation under Simultaneous Biaxially Stretching Using a Lattice Model and the Application of Oriented Crystallization of Polyethylene Films

Bin

Koganemaru

Nakashima

et al. 2005

Polym J

Self Cite

View full text Add to dashboard Cite

ABSTRACT:A lattice model proposed before for uniaxial stretching of polyethylene films was applied to estimate the oriented crystallization of ultra-high molecular weight polyethylene (UHMWPE) dry gel films under simultaneous biaxially stretching. In this model system, the preferred axis associated with the preferred orientation of amorphous chain segments was chosen along the direction between two successive cross-linked points and the preferred axis was assumed to deform in an affine fashion with respect to the stretching direction. As the application of the proposed model, the orientation distribution function of crystallites was calculated on the basis of the lattice model and oriented crystallization model. The oriented crystallization model is based on the concept that a kinetically determined distribution of crystal chain axes as the normalized distribution of clusters found at the saddle point corresponding to a non-uniform orientation under conditions of a steady-state nucleation rate. Of course, the crystallites are oriented randomly with respect to the film normal direction. The parameter fitting for the formulated orientation distribution function of crystallites was done for the film which was prepared by the gelation/crystallization from solution with 0.9 g/ 100 mL concentration, the solvent being decalin, since the concentration assured the highest drawability under simultaneous biaxially stretching. The calculated orientation distribution functions 2q j ðcos j Þ of the reciprocal lattice vector of the crystal planes were in good agreement with the observed ones. Thus the numerical calculations indicate that the orientation of the c-axes depends on that of amorphous chain segments and the orientation behavior of crystallites is strongly affected by their rotation around the c-axis. [DOI 10.1295/polymj.37.192] KEY WORDS A Lattice Model / Simultaneous Biaxially Stretching / Preferred Orientation / A Steady-State Nucleation Rate / Orientation Distribution Function of Crystallites / Segmental orientation in uniaxially deformed elastomatic networks has been treated in terms of gas-like theories and liquid-like theories.1-4 In the gas-like theories, the chain vector and segment vector distributions have been estimated theoretically by using idealized models in which the effect of mutual interference between chain segments are neglected. On the other hand, in a liquid-like theory, 3,4 the effect of intermolecular interferences relating to orientation-dependent packing entropy was taken into consideration based on a lattice model. Erman et al. 5,6 have attempted to improve the liquid-like theory by considering the effect of chain stiffness on segmental orientation. For this purpose, they adopted the lattice theory of Flory 7,8 for chains with freely jointed rod-like segments and applied it to a thermotropic system with anisotropic polarizabilities. Namely, Erman et al. pointed out that a segment of polyethylene chains with 1-22 bonds may be viewed as a rod-like object on the basis of the concept of Flor...

show abstract

Section: Application To Oriented Crystallization Of Polyethylene Undesupporting

confidence: 79%

Section: Characteristics Of Test Specimensmentioning

confidence: 93%

Section: Experimental Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Segmental Orientation under Simultaneous Biaxially Stretching Using a Lattice Model and the Application of Oriented Crystallization of Polyethylene Films

Bin

Koganemaru

Nakashima

et al. 2005

Polym J

Self Cite

View full text Add to dashboard Cite

show abstract

“…Namely, the considerable -dependence in Figure 6 is due to the specific rotation of crystallites around the c-axis as has been observed for the orientation of crystallites of polyethylene films. 16 If !ð; Þ shows a circular contour map with a maximum peak at ¼ 90 , all 2q j ðcos j Þ of the ðhk0Þ planes must show the same curves indicating random orientation of crystallites around their c-axis.…”

Section: Resultsmentioning

confidence: 99%

Orientation Distribution Functions of the Three Principal Crystallographic Axes as well as Crystallites of Poly(ethylene terephthalate) Films under Biaxially Stretching

Bin

Oishi

Yoshida

et al. 2004

Polym J

Self Cite

View full text Add to dashboard Cite

ABSTRACT:The orientation of the three principal crystallographic axes, the a-, b-, and c-axes of crystallites of poly(ethylene terephthalate) (PET) under simultaneous biaxial stretching was estimated in terms of the orientation distribution function. For most of crystalline polymers with a triclinic unit like PET, there are no crystal planes perpendicular to the a-, b-, and c-axes that can be detected directly by X-Ray diffraction techniques. Accordingly, the functions of the a-, b-, and c-axes must be calculated by the method proposed by Roe and Krigbaum. In doing so, the orientation functions of the reciprocal lattice vectors must be measured for a number of crystal planes. In this paper, as an example, the orientation of crystallites and the orientation of the a-, b-, and c-axes were estimated for a PET film under simultaneous biaxial stretching in terms of the orientation distribution function of crystallites because of considerable utilization rate of PET as commercial films. The estimated orientation functions of the b-and c-axes predicted the detailed information concerning uniplanner orientation of benzene rings parallel to the film surface. [DOI 10.1295/polymj.36.394] KEY WORDS The Three Principal Crystallographic Axes / Poly(ethylene terephthalate) / Simultaneous Biaxial Stretching / Orientation Distribution Function of Crystallites / Benzene Rings / The evaluation concerning molecular orientation was first proposed by Herman in terms of the second order orientation factor.1 This factor is a sort of the second moment of the orientation function. After then, the orientation of crystallites was estimated by Roe and Krigbaum 2-4 in terms of the distribution function. The mathematical representation was given by an expansion of the distribution function in a series of generalized spherical harmonics. This method has been very important to obtain the orientation of the three principal crystallographic axes, the a-, b-, and c-axes, in terms of the orientation distribution function. Actually, there are several papers for estimating orientation distribution functions of the three principal crystallographic axes, the a-, b-, and c-axes of polyethylene, 5,6 poly(vinyl alcohol), 7,8 nylon 6 9 and cellulose. 10The first trial for poly(ethylene terephthalate) by Krigbaum and Balta 11 was done by using a simple uniaxially stretched films but their trial was absolutely unsuccessful. However, the recent development of computer program and high power X-Ray source provide easy peak separation of overlapped peaks and the orientation functions for the reciprocal lattice vectors can be obtained for a number of crystal planes with high accuracy. Consequently it becomes possible to calculate the orientation distribution functions of crystallites as well as of the a-, b-, and c-axes from the observed orientation functions of the reciprocal lattice vectors of the crystal planes. In previous paper, 12 the orientation of crystallites with a triclinic unit was evaluated in terms of orientation distribution function for a PBT fi...

show abstract

Morphology and High Modulus of Laminated Ultra‐Drawn Polyethylene Films with Biaxial Orientation Prepared by Microwave Heating

Azuma

Chen

Nakano

et al. 2007

Macro Materials & Eng

Self Cite

View full text Add to dashboard Cite

To improve the poor mechanical properties of uniaxially ultra‐drawn films along the transverse direction, lamination of two ultrahigh molecular weight polyethylene/ethylene dimethylaminoethyl methacrylate copolymer blend films was carried out in the rectangular elongation direction by a microwave heating method. The characteristics of the successful laminated films were analyzed theoretically and experimentally. The original orientation of the crystallites for the blend films was maintained perfectly after lamination, and the preferential directions intersected each other. The Young's modulus increased symmetrically with respect to the 45 ° direction. This is the first report concerning a drastic improvement of the Young's modulus in the transverse direction for films ultra‐drawn along one direction.magnified image

show abstract

Morphology and Orientation of Crystallites of Simultaneous Biaxially Stretching Ultra-High Molecular Weight Polyethylene Films Prepared by Gelation/Crystallization from Solutions

Cited by 10 publications

References 44 publications

Segmental Orientation under Simultaneous Biaxially Stretching Using a Lattice Model and the Application of Oriented Crystallization of Polyethylene Films

Segmental Orientation under Simultaneous Biaxially Stretching Using a Lattice Model and the Application of Oriented Crystallization of Polyethylene Films

Orientation Distribution Functions of the Three Principal Crystallographic Axes as well as Crystallites of Poly(ethylene terephthalate) Films under Biaxially Stretching

Morphology and High Modulus of Laminated Ultra‐Drawn Polyethylene Films with Biaxial Orientation Prepared by Microwave Heating

Contact Info

Product

Resources

About