双块共聚合物化的热处理模仿了金
Kyungtae Kim1, Morgan W Schulze1, Akash Arora1
1Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455-0132, USA.
概括
聚异乙烯聚乳酸二块共聚物的热史决定了它们的最终结构. 特定的冷却方法可以导致独特的晶体或准晶体状态,包括金属合金Laves阶段.
科学领域:
- 聚合物科学
- 材料科学
- 晶体学
背景情况:
- 聚合物自我组装对于先进材料至关重要.
- 了解加工对聚合物形态的影响是关键.
- 低质的双块共聚物具有可调节的特性.
研究的目的:
- 调查热史对聚乙烯-聚乙烯-乳酸共聚合物的形态的影响.
- 探索晶体和准晶体状态的形成.
- 阐明冷却速度和火在结构发展中的作用.
主要方法:
- 小角度X射线散射 (SAXS) 的实验.
- 控制冷却和灭的协议.
- 自相一致的平均场理论 (SCMF) 的计算.
主要成果:
- 在共聚物自组合中观察到异常的热史依赖性.
- 直接冷却产生了记录的形态.
- 快速火,然后加热,形成六角C14和立方C15的Laves阶段.
- 弗兰克-卡斯珀阶段是可访问的,并显示几乎退化的自由能量.
结论:
- 处理历史是这些共聚物中变态稳定的关键决定因素.
- 形成了具有离散体积和多面体形状的自我组装粒子.
- 这些发现为通过热处理设计复杂的聚合物架构提供了见解.
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