结晶和融化含有悬挂的不纠的聚乙烯-烯酸) 循环
Liuyong Zhu1,2, Jingqing Li2, Hongfei Li1,3
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China. hfli@ciac.ac.cn.
Soft matter
|July 20, 2023
概括
循环聚合物表现出独特的结晶和化行为,这是由于悬挂组影响链条动力学. 这项研究揭示了循环多-烯酸中的转移性结构和带状球体,为聚合物结晶提供了新的见解.
科学领域:
- 聚合物科学与工程 聚合物科学与工程
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 罗斯模型对于线性,不纠的聚合物是有效的,但循环聚合物中的链动态不同.
- 晶体形态与链动力学和结晶动力学密切相关.
- 了解循环聚合物的行为对于开发先进材料至关重要.
研究的目的:
- 在临界分子量 (Mc) 附近合成循环多-ε-caprolactone (c-PCLs) 与双基链.
- 研究这些c-PCL的结晶和融化行为,重点关注链条动力学.
- 探索悬挂组在加热过程中对晶体形态和结构演变的影响.
主要方法:
- 合成具有特定分子重量和悬挂组的循环聚ε-罗拉克.
- 差分扫描热量计 (DSC) 用于分析热过渡.
- 极化光学显微镜 (POM) 用于形态观测.
- 在现场同时进行小角度X射线散射/广角X射线散射 (SAXS/WAXS),用于结构进化研究.
主要成果:
- 在结晶c-PCLs的DSC加热曲线中观察到双个内热峰值,特别是那些具有Mc的.
- 在现场SAXS/WAXS揭示了加热过程中的结构演变,与DSC发现相关.
- 首次在未纠的c-PCL中观察带状球体,这表明链动力学和结晶动力学之间的不匹配.
结论:
- 悬挂组显著影响循环聚合物中的链动态,导致转移稳定的结构的重组.
- 观察到的双重内热峰和带状球体突出显示了循环聚合物的独特结晶行为.
- 研究结果提供了对聚合物链架构,动力学和晶体形态学之间的关系的基本见解.
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