Photon Factory Activity Report 2004 #22 Part B (2005)
Materials Science

15A /2004C004

Equibiaxial drawing behavior of isotactic polypropylene film by time-resolved
WAXS/SAXS measurements
Takashi SAKURAI1*, Yoshinobu, NOZUE1, Tatsuya KASAHARA1, Noboru YAMAGUCHI1
and Yoshiyuki AMEMIYA2
1
Petrochemicals Research Laboratory, Sumitomo Chemical Co., Ltd., 2-1 Kitasode Sodegaura City,Chiba 299-0295, Japan
2
Graduate School of Frontier Sciences, Univ. of Tokyo, Kashiwanoha, Kashiwa City, Chiba 277-8561, Japan

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Experimental
As a typical example, we used here a commerciallyavailable Zieglar-Natta iPP with Mw of 4.5 × 105 g/mol,Mw/Mn of 5.1, melt flow rate index of 2 g/10min, and amelting temperature of 163 °C.
The specimen (20mm×20mm×0.5mmt) was preparedby pressing at 230 °C followed by cooling to room
temperature. In Figure 1, we briefly present the set up of
newly designed biaxial film drawing machine.
Equibiaxial drawing tests were carried out at temperature
close to melting point (160 °C) and draw rate of 1mm/sec.
The WAXS and SAXS measurements were conductedat the BL-15A beam line. For tracing the structuralchange in the specimen during drawing, time-resolved
two-dimensional (2D) WAXS and SAXS patterns weremeasured with 0.5 sec time slices by using a CCD X-ray
detector [2].

Results and Discussion
Figure 2 shows the time dependence of WAXS andSAXS profiles on the horizontal line. The WAXS
intensity became gradually weaker and finally notdetective. The peak position was constant during drawing.
The peak position of SAXS shifted to lower scattering
angle, being accompanied with the decrease in peakintensity. No anisotropy was observed for 2D WAXS
and SAXS patterns, respectively. These results suggestthat the chain axes of crystalline chains orient into eachdirection of drawing.

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Introduction
Considerable work has been reported to investigate thestructural deformation of isotactic polypropylene (iPP)
over a wide range of strain and temperature. However,most of the research about deformation reported in theliterature is uniaxial. In real industrial processes such as
blow molding and film stretching, iPP is often deformed
under much more complex strain fields than simple
uniaxial drawing. It is therefore of significant importanceto investigate how the microstructure of iPP subjected tothe complex strain field evolves, in particular, in biaxial
drawing processes [1].
Recently, we have developed newly designed biaxial
film drawing machine and have successfully applied forin-situ time-resolved measurements of wide- and smallangle X-ray scattering (WAXS and SAXS, respectively)in order to trace the structural evolution of iPP during
equibiaxial drawing.

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Figure 2 The time dependence of (A) WAXS and (B)
SAXS profiles on the horizontal line obtained fromWAXS and SAXS patterns

Figure 1 Newly designed biaxial film drawing machine

References[1] T. Lüpke et al., Polymer 45, 6861 (2004).
[2] Y. Amemiya et al., Rev. Sci. Instrum. 66, 2290 (1995).
* sakurait2@sc.sumitomo-chem.co.jp

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