Abstract: Ring-banded spherulites in crystallization of poly( ε-caprolactone) and poly(styrene-random-acrylonitrile) blends were observed with polarizing optical microscopy and digital image analysis technique was applied directly to the image obtained by polarizing microscope. Several new interesting phenomena were found. One is that the ring-banded structure is still clearly seen after the analyzer was removed and this astonished phenomenon couldn't result from the general concept about formation mechanism of ring-banded spherulite——lamellae twisting. Another one is that there is a slight, dark line in the bright band when cross polars were added, which may be related to the formation process and mechanism of ring-banded spherulites in the blends of poly( ε-caprolactone) and poly(styrene-random-acrylonitrile).

Key words: Poly( ε-caprolactone), Poly(styrene-random-acrylonitrile), Ring-banded spheru-lite