We succeeded in elongational crystallization of isotactic polypropylene (iPP) by compressing the supercooled melt. When the elongational strain rate (
) surpassed a critical value (
*=2×102 s−1), crystallization behavior and structure discontinuously changed. The induction time decreased by 10−6 times (Figure), the crystal size decreased by 10−3 times and morphology changed from spherulites to ‘nano-oriented crystals (NOCs)’. It is concluded that large
induced the ‘oriented melt’ and NOCs. The NOCs showed high crystallinity and ultra-high performances, such as high tensile stress (210 MPa).
- Kiyoka N Okada
- Jun-ichiro Washiyama
- Masamichi Hikosaka
