Photon Factory Activity Report 2004 #22 Part B (2005)
Instrumentation and Technique

15A/2003G239

Combined Measurement of SAXS and Dynamical Viscoelasticity on FilledRubber
Yuya SHINOHARA*1, Hiroyuki KISHIMOTO2, Kentaro
KAYASHIMA1,1
and Yoshiyuki AMEMIYA
1The UniversityofTokyo,
5-1-5
Kashiwanoha, Kashiwa, Chiba 277-8561, Japan2
SRI Research & Development ltd., Kobe, Hyogo, Japan
Introduction
It is widely known that the addition of filler such ascarbon black and silica to an elastomer shows thereinforcement effect, which increases modulus ofelasticity, tear strength, tensile strength, cracking
resistance, and fatigue resistance [1]. The reinforcement
effect has been extensively investigated since its
discovery on 1904, although its mechanism has not beenclarified yet. Filler composes hierarchical aggregate
structure as shown in Fig.1. The aggregate structure offiller would be the origin of the reinforcement.
Conventional methods such as TEM and light scattering
are inappropriate for the study of filled rubber, because
TEM is not suited to time-resolved measurement and lightscattering is not applicable to opaque specimen. SAXSovercomes these difficulties and would become a major
tool for the study of filler aggregate. By using ultra-SAXS,
we showed that the aggregate structure of stretchedrubber was anisotropic in micron-scale [2]. However, inorder to understand the effect of aggregates on thereinforcement, we have to investigate the aggregate
structure over a wide size-scale. We now investigate theeffect of filler aggregate structure on the reinforcement,by using small-angle X-ray scattering (SAXS), In thisstudy, we attempted to measure the SAXS and theviscoelasticity of filled rubber simultaneously.
Experimental
The sample used was Styrene-Butadiene rubber filledwith various types of carbon black and silica particle. Thethickness of sample was around 1 mm.
Experiments were performed at BL-15A. The
schematic of the experiment setup is shown in Fig. 2. The
X-ray wavelength was 1.50 A. An X-ray Image Intensifier(150 mmφ) coupled X-ray CCD detector [3] was used asa detector. The sample-to-detector distance was around2000 mm, which was calibrated with the scattering peakof silver behenate. We measured time-resolved SAXS
simultaneously with dynamic viscoelasticity. The sample
was set at the dynamic viscoelastic instrument, whichenables X-rays to pass through the samples. The exposureand the strain of the sample were controlled with thestimulator installed at BL-15A. The sample temperature
was controlled by the viscoelastic instrument at -30 °C, 0°C, 20 °C, 70 °C. The cycle of elongation was 100 ms,
and the SAXS was recorded every 10 ms. The maximum
elongation ratio was 2, which was defined by the ratio ofthe elongation length to the initial length.

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Users' Report

Results & Discussion

Fig.1: The hierarchical structure of filler in rubber.
Primary particles compose aggregate and theaggregates compose agglomerate.

Fig. 2: Experimental setup. The sample was set at the
dynamic viscoelastic instrument. SAXS was recordedwith XRII-CCD. The exposure and the strain ofsamples were controlled with the stimulator.
We have successfully measured both SAXS anddynamic viscoelasticity simultaneously. The scattering
intensity profile largely depends on the filler types, which
would be a key for the understanding of the reinforcement.
However, neither the change of intensity profile with theelongation nor the anisotropic scattering pattern, whichwere observed in ultra-SAXS, are not observed. Theseresults show that the change of aggregate structure greatly
depends on the size-scale.
References[1] J. D. Ferry, "Viscoelastic Properties of Polymers",
John Willy & Sons, New York, (1980).
[2] Y. Shinohara et al., SPring-8 User Exp. Report No. 13,(2004)[3] Y. Amemiya et al., Rev. Sci. Instrum. 66, 2290, (1995)* shinohara@x-ray.k.u-tokyo.ac.jp