Fig. 4. SEM micrograph of the composites PS/VA 70/30 (percent by weight) (a) and PS/VA 40/60 (percent by weight) (b). The skin area
is on the left and the core area on the right of the micrographs (a) and (b).
Acknowledgements This work was support by the National Natural
Science Foundation of China (Grant No. 59873026).
The structure shown in fig. 4(a), (b) is similar to that
of some materials found in nature such as animal bones,
[
14]
bamboo and wood . These natural materials have a
compact and high-strength skin layer to support external
loads, while their porous cores keep their toughness and
decrease the whole weight. These two regions interact
with each other to exhibit excellent performances of the
resultant material. The PS/Vercta A950 composites in the
present study have a biomimetic structure: in the outer
skin area are highly oriented liquid crystal polymer fibrils,
and in the core area is mainly the PS mcirocellular mate-
rial. In this skin-core microcellular polymer composite,
the liquid crystal polymer fibrils may give the material
high strength and the microcellular PS in the core gives
toughness and heat insulation. So these PS/Vectra A950
composites combine advantages of microcellular PS and
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: a sustain-
A microcellular composite with a skin-core structure
2
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The material has a biomimetic structure like bamboo and
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2
SC-CO . The thickness of the skin can be controlled by
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(Received October 30, 2000)
Chinese Science Bulletin Vol. 46 No. 11 June 2001
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