Nonequilibrium Nature of Flow-Induced Nucleation in Isotactic Polypropylene

被引：83

作者：

Cui, Kunpeng ^{[1
,2
]}

Liu, Dong ^{[1
,2
]}

Ji, Youxin ^{[1
,2
]}

Huang, Ningdong ^{[1
,2
]}

Ma, Zhe ^{[3
]}

Wang, Zhen ^{[1
,2
]}

Lv, Fei ^{[1
,2
]}

Yang, Haoran ^{[1
,2
]}

Li, Liangbin ^{[1
,2
]}

机构：

[1] Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei 230026, Peoples R China

[2] Univ Sci & Technol China, Coll Nucl Sci & Technol, CAS Key Lab Soft Matter Chem, Hefei 230026, Peoples R China

[3] Eindhoven Univ Technol, Dept Mech Engn, NL-5600 MB Eindhoven, Netherlands

来源：

MACROMOLECULES | 2015年 / 48卷 / 03期

基金：

中国国家自然科学基金;

关键词：

EXTENSION-INDUCED CRYSTALLIZATION; X-RAY-SCATTERING; SHISH-KEBAB; INDUCED PRECURSORS; FLUCTUATION; TRANSITION; NETWORKS; POLYMERS; DYNAMICS; STRAIN;

D O I：

10.1021/ma502412y

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 [高分子化学与物理];

摘要：

Based on classical nucleation theory, the current entropic reduction model (ERM) of flow-induced crystallization (FIC) treats external work as perturbation on the framework of equilibrium thermodynamics, which, however, obscures the nonequilibrium nature of FIC. In this work, in situ investigation on FIC under strong flow by combining a unique homemade extensional rheometer and ultrafast X-ray scattering reveals a constant critical strain or time for nucleation in isotactic polypropylene melt in a wide temperature range from 130 to 170 degrees C. Our discovery contradicts the straintemperature equivalence predicted by ERM but unveils the nonequilibrium nature of FIC. To account for the temperature independence of flow-induced nucleation, a tentative kinetic pathway of nucleation describing stretch-induced hierarchical structural transitions is proposed through which the capability of flow as driving force is justified.

引用

页码：694 / 699

页数：6

共 43 条

[1]

Shear-induced conformational ordering, relaxation, and crystallization of isotactic polypropylene [J].