期刊首页 优先出版 当期阅读 过刊浏览 作者中心 关于期刊 English

《化学科学与工程前沿(英文)》 >> 2009年 第3卷 第1期 doi: 10.1007/s11705-009-0002-2

Lamellar thickness transition of melt-crystallized polybuten-1 tetragonal phase: configurational change in chain folding directions

College of pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan

发布日期: 2009-03-05

下一篇 上一篇

摘要

Lamellar crystal thickness of isotactic polybutene-1 ( -PB1) have been investigated for crystallization in the melt over a wide range of crystallization temperature from 40°C to 90°C by small angle X-ray scattering experiments and density measurements. The crystal thickness demonstrates two linear dependences on inverse supercooling and a transition from one dependence to the other has been observed around = 65°C. Each of the two dependences obeys the nucleation theory in the high and low supercooling ranges, respectively. Chain folding free energy determined from the low supercooling range is larger than that determined from the high supercooling range. Possible mechanisms for the transition are discussed taking account of entropy of chain folding directions.

相关研究