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Form II to form I transition in solution-crystallized isotactic polybutene-1
Peng Fu1, Jiaxin Huo1, Jingqing Li1
1School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China. scjiang@tju.edu.cn.
Soft Matter
|March 26, 2024
Summary
Crystallization temperature and heating rate influence polybutene-1 crystal transitions. Lower crystallization temperatures lead to faster form II to form I transitions, highlighting the role of conformational entropy in amorphous regions.
Area of Science:
- Polymer Science
- Materials Science
- Crystallography
Background:
- Polymer chains exhibit dynamic conformations and entropy in solution or melt states.
- Crystallization restricts polymer chain conformations and associated entropy.
- Conformational entropy is linked to chain dynamics and energy-dependent conformational changes.
Purpose of the Study:
- To investigate the influence of precipitation temperature and heating rate on the crystallization and transition of isotactic polybutene-1 (iPB-1).
- To understand the role of conformational entropy in the amorphous regions of iPB-1 during crystal transitions.
Main Methods:
- Isotactic polybutene-1 (iPB-1) was crystallized from solution using a precipitant at varying temperatures.
- Solution-crystallized iPB-1 was heated to 100 °C at different heating rates to induce form II.
- The transition of iPB-1 form II to form I was characterized.
Main Results:
- The transition from iPB-1 form II to form I is dependent on both precipitation temperature and heating rate.
- iPB-1 crystallized at lower temperatures exhibits a faster form II to form I transition.
- The formation temperature of form II is determined by both precipitation temperature and heating rate.
Conclusions:
- Both precipitation temperature and heating rate are critical factors in determining the final crystal form and transition behavior of iPB-1.
- The conformational entropy of the amorphous regions in iPB-1 plays a significant role in understanding its crystal transition mechanisms.
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