Precursor of Shish-Kebab above the Melting Temperature by Microbeam X-ray Scattering

Preparation of strong fiber with ultrahigh strength and modus is a dream of polymer scientists and engineers. It is believed that a shish-kebab is the structure origin of the ultrahigh strength and modulus fiber. This article presents our investigation on the inner structure of shish-kebab precursor of isotactic polystyrene in μm scale formed by shear flow above the nominal melting temperature T m using microbeam wide- and small-angle X-ray scattering (WAXS and SAXS). The microbeam WAXS experiments indicated that the precursor included crystallites with degree of crystallinity of ∼0.15%, which had higher melting temperature than normal lamellar crystals, meaning that its size (the length) was longer in the c -axis of crystals than the normal lamellar crystals. The microbeam SAXS experiments confirmed that approximately 1% of the crystallites in the precursor were rather long in the direction of c -axis. It is expected that such crystallites work as an initiator of a shish when it is below T m .